"These are some of the world's greatest monuments." "They combine colossal mass with precision engineering." "For over 4,000 years they were unsurpassed." "Yet they were built by peasant societies with only simple tools." "And the Egyptians weren't alone." "Pyramids were the crowning achievements of other civilizations around the world." "The search for treasure has always brought thieves and bounty hunters to the pyramids." "But for today's explorers the challenge is to reveal the amazing stories of the people who built them." "Rush hour, Mexico City." "In the main square, Aztec dancers are in less of a rush." "Under their feet, covered by the modern streets, lies an older capital a lost city of high-rise pyramids." "To track down their remains you need something a little like X-ray vision." "Some folk walk their dogs." "Archaeologist Dr. Luis Barba prefers a quiet stroll with his ground-penetrating radar." "It has a nose for old ruins scanning the ground with bursts of energy that bounce back off buried objects." "These reflected signals are helping Barba to see through the modern city shown here in white, and map its Aztec counterpart underneath." "In a few places, excavation has stripped away the new to reveal the old." "At the heart of the Aztec capital stood a huge double pyramid." "Rising above the surrounding temples and plazas it was the centerpiece of a city whose scale and splendor outstripped anything in Europe." "To the Spanish who came here in 1519 it was a miracle." "But what is a pyramid?" "And where else can you find them?" "Let's get this clear when we're talking pyramids we're talking big." "This Mexican one, for example climbs to a height of eight stories and packs around 4,000 tons of rubble and masonry." "And size dictates shape." "With basic technology, the only safe way to build tall is to slope the sides inwards to an apex." "There may be variations." "Some pyramids have steps and a flat summit for a temple." "Nevertheless, the basic pattern can be traced across four continents." "In China, around 200 B. C, the First Emperor was buried under an immense earth pyramid." "It's a mile around and took a workforce of 700,000 to accomplish." "Buried close by, the Emperor had a private army of clay warriors on permanent stand-by to guard his tomb." "Across the world, to North America and in the fertile Mississippi valley of Illinois the native Cahokians were also thinking big." "A thousand years ago, they built this gigantic pyramid mound around ten stories high." "Travel south and large pyramids can still be found through Central America, and in Peru." "But the cradle of pyramid building is in Africa, on the banks of the Nile." "Who would guess, though, that most of the pyramids here were built not by Egyptians, but by Nubian kings to the south?" "The broken stumps of their pyramids lie here, in what is now Sudan." "But we're jumping the gun." "The pyramid story begins a thousand miles down river, in Egypt itself." "So complete do they appear and so majestic it seems that Egypt's pyramids sprang from thin air." "The truth is less romantic they built a lot of cars before the Rolls Royce." "In a bleak stretch of desert at a place called Abydos archaeologists have come back to re-excavate the tombs of Egypt's earliest rulers, from 5,000 years ago." "Perhaps a vital clue to the origin of the pyramids was overlooked." "It's hardly glamorous, but sifting old evidence has paid off." "At the re-opened tomb of King Khazekhemwy" "Gunter Dreyer of the German Archaeological Mission has noticed something odd." "In Khazekhemwy's tomb we have a remarkable discrepancy in the preservation of the height of the walls." "In this part, the northern part the walls are still preserved up to the original height of about two meters." "The level of the ceiling was about here." "Whereas in this part of the tomb the walls are squashed down to about half of the original height." "But nothing is missing of the walls here as we still have the remains of the wooden roof beams in place." "Obviously, the walls are squashed down completely by a heavy extra weight in this area." "This heavy extra weight, according to Dreyer's reconstruction was a large burial mound a superstructure of some kind placed above the center of Khazekhemwy's tomb." "A proto-pyramid, perhaps." "A mile from the tomb is a vast and puzzling enclosure." "Its gigantic mud brick walls rise 30 feet, yet there's nothing left inside." "Whatever this was it's clear that Khazekhemwy liked his buildings on a monumental scale." "But he wasn't the first to build a pyramid." "That honor goes to his successor King Djozer." "Buried far to the north of Abydos this was the man who launched the Pyramid Age." "At Abydos we had, below desert level the tomb pit and above desert level, the mound." "And a large enclosure at some distance from the royal tomb." "Djozer for the first time built the enclosure around the tomb." "But then there was a problem." "The mound was no longer visible because it was covered by the surrounding enclosure wall." "An easy escape was to build another mound on top of the old one and add another." "And that's how the step pyramid developed." "With its six-step pyramid" "Djozer's tomb complex is the world's oldest piece of large-scale stone architecture." "It dates to around 2,600 B.C." "The pyramid itself, around 20 stories high was a giant stepping stone towards the classic design." "For the next 1,000 years flat sides would be fitted as standard." "The reason is anyone's guess." "Perhaps they symbolized the rays of the sun making a ramp to heaven." "Whatever the intention it was this man, King Sneferu who pioneered the new geometry." "But with his first serious attempt things took a turn for the worse." "This bulky prototype was too heavy for the soft desert sand and threatened to cave in under its own weight." "Its top had to be bent in and the result, frankly was a bit of a mess." "Back to the drawing board." "Sneferu tried once more to fulfill his vision." "This time the pyramid was set on a rock foundation and he played it safe with the slope." "The result was the world's first true pyramid." "It hasn't aged so well." "A better impression is conveyed by its ancient name, the "Shining Pyramid"." "By day, its white stone casing would have shimmered." "This was the dawn of the pyramid's Golden Age." "Pyramids would reach their all-time peak a few miles north on the Giza Plateau, by modern-day Cairo." "It was here that two of Sneferu's sons Khufu and Khafre, built the world's biggest pyramids." "Each is around 50 stories high." "But before the building work began there was a vital job for the surveyors." "Lining up a pyramid was critical." "To the pharaohs, the gateway to eternity was the center of the heavens where the stars never set." "Though colossal, the pyramids were aligned to these sacred stars with astonishing precision to within fractions of a degree." "How was it done?" "The crucial clue is this progressively, the alignment of pyramids gets worse." "This paradox has recently been solved and along with it, the ancient method of alignment all thanks to modern astronomy." "As the Earth spins on its axis it wobbles imperceptibly over thousands of years." "This wobble slowly alters our view of the night sky from Earth." "From Egypt today, the heavens appear to revolve around the pole star." "But when the pyramids were built that pivotal point lay elsewhere." "There was no bright star to mark this point yet for the pharaohs it was vital to be on target and it seems they used a combination of two stars, Mizar, in the Big Dipper and Kochab, in the Little Dipper." "Two and a half thousand years B. C these two stars circled opposite each other." "Once each night they spanned the pole one star dead above its twin." "By holding a plumbline to them and extending this to the horizon an Egyptian surveyor could fix a baseline for the pyramid that would angle it precisely to the center of the heavens." "Neat, only it didn't allow for the Earth's wobble." "As the night skies shifted the surveyors stuck to Kochab and Mizar for their bearings." "Exaggerating the shift, which was imperceptible to the naked eye we can see why successive pyramids turn steadily eastwards." "Solving the mystery of alignment is one thing." "Can we also discover how the pyramids were built?" "The 'Great Pyramid' at Giza contains well over two million blocks mostly weighing around two and a half tons." "It took some 23 years to build which means that on average one block had to be added every couple of minutes." "A tough delivery target to put it mildly." "How was it met, with only simple cutting tools, and no machinery for lifting?" "The workmen were grouped into gangs each a thousand strong." "And they weren't slaves as once supposed." "They were paid labor." "But the question remains." "How did the Egyptians move so much stone so quickly?" "Paintings show that royal statues and other single massive objects were hauled on sleds pulled by hundreds of men." "But can this be how millions of pyramid blocks were moved?" "Speed was paramount." "The pharaoh's death was an unbreakable deadline." "So the bigger the pyramid the greater the rush." "Modern trials show that sleds are slow and awkward at the best of times." "Even with modest-sized blocks." "To a modern engineer, sleds make no sense at all." "Well I think, anyone who's done a little bit of first year engineering mechanics will realize that sleds are a highly ineffiicient way of moving any heavy objects because of the problems with friction and problems with maneuverability and so on." "Anybody who could build pyramids had to be smart and they could certainly have come up with a better solution." "The whole logistics of building the pyramids demanded a high-tech solution." "And there's another problem with the sled theory." "Everyone agrees that blocks were moved up the growing pyramid on specially built ramps." "The problem with hauling them on sleds is that the ramp has to be shallow rising only a step or so for every ten steps forward." "Such a gentle, one-in-ten slope would require an immense length of ramp." "A steeper gradient, say one-in-four would shorten the ramp." "But it would also rule out sleds." "Is there a plausible alternative to sleds?" "Archaeological deposits have yielded numerous wood models of ancient building equipment including a rather enigmatic artifact." "This rather curious cradle-like device was found in such a deposit of the construction equipment models and I think it provides the clue to how the pyramids were built." "The Egyptian technology is revolutionary, quite literally." "On a small-scale model four of these cradles strap to the sides of a concrete brick to make a circular runner." "With two such runners the brick can roll." "I think even the most ardent sled fans would have to agree that it's unrealistic to try and pull a sled up a slope much steeper than one in ten whereas if you are rolling a heavy object you can roll it up a ramp of, say one in four." "To prove that claim, Parry has teamed up with some fellow engineers in Japan." "On a one-in-four slope if you had a two and a half ton block on a sled it requires something like 60 to 80 men to pull it which would be out of the question when you've got many stones" "being hauled at any one time." "But with a rolling system you need only a quarter of the manpower." "The tests that we did in Japan showed you could roll a two and a half-ton block up a one in four slope 15 meters long in less than a minute." "If the Egyptians had figured out rolling, then the old sled theories are on a slippery slope." "That all this sweat and toil was for one man's burial gives us an insight into the power of the pharaoh." "His finished pyramid was a resurrection machine a spirit transporter, to whisk him to the stars." "The king's mummified body was taken through a narrow passage into a vaulted tomb chamber." "It was precision engineering inside and out." "But that's not all." "Around the pyramid itself, within a walled compound there were temples, shrines and storage rooms." "From here, a corridor ran like a giant pipe down to the Nile where it could tap the best of Egypt's produce." "For long after the pharaoh's death a nonstop stream of goods poured in." "It was the job of the priests to mind the king's spirit serving up a daily mix of fresh food and prayers." "A royal spirit wouldn't go hungry." "But it was only safe as long as its earth-bound body inside the pyramid could well in peace." "High security granite sealed off the tomb." "But all to no avail." "The giant pyramids at Giza were soon robbed of treasures we can only imagine." "The thieves, though, may have sparked a big change in pyramid design." "For all their colossal size these hulks had failed to protect." "And abruptly the pharaohs changed tack ...drastically scaling down their pyramids." "Compared to the mammoth creations at Giza, visible behind the later pyramids are small, a tenth or less the size of their forerunners." "From now on, pharaohs would travel to the stars economy class." "It's a puzzle that archaeologists are still debating why did pyramids shrink?" "Vassil Dobrev has scrutinized these smaller pyramids and thinks the answer is down here inside the tomb chambers." "A very striking difference that you see inside the smaller pyramids is that there are hieroglyphs cut into the walls of the tomb." "Literally thousands and thousands of signs." "At Giza, we get absolutely nothing like this inside the pyramids." "When we actually decipher these inscriptions we discover that they are formulas or spells for the resurrection of the king." "There are spells of all kinds." "The pharaoh, some say, shall follow the destiny of the polar stars to eternal life." "For Dobrev, such spells were the pharaoh's new insurance policy more reliable than a fortress of stone." "Once the king had these spells inside his tomb it was not necessary any more to build a big, big pyramid." "He had a much better protection." "At least, that's what he thought." "But others disagree." "At his excavations in a non-royal tomb" "Miroslav Barta is finding evidence to back up a much bigger claim." "What shrank first, he argues, was the pharaoh's power." "The finely painted tombs of state offiicials bear witness to a new era." "Classy burials were no longer the sole preserve of royalty." "While their predecessors at Giza had to make do with mud brick these offiicials went high spec with the finest stone a material once reserved for kings." "To Barta, it's no coincidence." "State offiicials were gaining in power and wealth at the expense of the pharaoh so that the only affordable pyramid was the budget model." "But Barta will need more than this to convince Dobrev." "Take the first three dynasties." "If you compare the material the decoration the architectural set-up you can see that the king always had the exclusive right to use stone for his projects." "Even the highest offiicials of the country had to use mud brick." "Yes, but how can we compare things that are different?" "We know that later pharaohs like Pepi the First married into the families of top offiicials maybe to boost their dwindling power." "A lot of power." "For instance that Pepi the First is forced to marry two daughters of a local offiicial from Abydos." "Well I don't know if he was forced." "Yeah, but he, he, he considered it necessary to ensure..." "Maybe it was just a nice girl, it she was beautiful" "Pepi the First, so why not?" "Yeah, but the brother of this offiicial became a vizier." "I don't believe a word about this..." "...because now we know that..." "Whichever way you argue it it wasn't over." "The shrinking pyramid was going to shrink again." "800 years later and 400 miles up river..." "Close to Thebes, the ancient capital of Egypt's New Kingdom an archaeologist Kent Weeks finds the final twist in the tale." "I suspect that most human societies have had some way of identifying different social classes." "But if you're going to have a class system you have to have a means of identifying what class an individual is part of." "That was certainly true in Egypt." "For a period of about 1,000 years pyramids were the symbol of the king and the immediate members of the royal family." "But maybe around 1900, 1800 B.C., there began a process that some people have called religious democratization which means that a lot of the things that had formerly been restricted to the pharaoh, the royal court now became increasingly available to ordinary members of Egypt's upper" "and middle class." "And that certainly took place with pyramid building." "Pyramids became high fashion and the nouveau-riche were quick to snap up the royal emblem." "Below ground, the tombs were smartly decorated with paintings of their proud owners." "Perched on top, the crowning glory was the pyramid." "Not a very big structure by any stretch of the imagination built of mud brick, not of huge limestone blocks." "But nevertheless it is a pyramid form." "And accompanying hieroglyphic texts tell who they were and why they were so important and so deserving of what only a few hundred years earlier had been a monument fit only for a king." "Half a million times smaller than the big guys these were the people's pyramids." "Structures on the mighty scale seen at Giza would never be raised again at least, not in Egypt." "Travel 8,000 miles southwest of Egypt and you cross two continents and an ocean to arrive at one of the driest places on earth." "In this coastal desert, the remains of ancient cultures still emerge from the shifting sands." "Welcome to the Americas." "It was along the coastline of South America, in what's now Peru and at around the time of Christ that the next great pyramid civilization would emerge." "For a stretch of 200 miles the desert is crossed by a half dozen or so rivers that run off the Andes." "Just like the Nile in Egypt each is a lifeline in an otherwise inhospitable land." "Surprisingly, though conditions here are ideal for intensive agriculture." "With little rain to wash away the topsoil the earth is fertile." "Irrigate it and crops grow abundantly." "I think the quality of agriculture was so good, that in fact it it permitted people to develop fairly big populations very rapidly." "And also it led to the creation of hundreds and hundreds of temples." "The area was settled by a people called the Moche who literally built upon the remains of earlier structures." "Their solid mud brick pyramids have long ago dissolved into shapeless lumps leaving only murky, crumbling faces that give no hint of what lies within." "It is still very diffiicult to understand the function of Moche pyramids because we haven't studied many of them yet and it takes years of excavations to really know what was going on there." "Steve Bourget has devoted 15 years to solving the mystery of the Moche pyramids." "From his latest excavations the outlines have now emerged of a colorful yet sinister story that could hardly be more different from ancient Egypt." "For decades the Moche were known mainly by their artwork especially by theirjewelry and by their richly decorated pottery." "Among the scenes depicted there are disturbing images of human sacrifice." "Were these just elaborate myths?" "Or were they documentary accounts of slaughter at the great Moche pyramids?" "My greatest breakthrough I think so far was the discovery of the sacrificial site itself." "That sacrificial site is at the so-called "Huaca de la Luna"" "the Pyramid of the Moon." "It was here that Bourget and his team found a jumble of human remains... of people who were brutally killed." "Significantly, perhaps there are signs of frequent and devastating floods at the very time of this mass sacrifice." "We saw that it was associated with destructive moments in their history these mega El Nino events with these gigantic rainfalls and destructive floods that they had on the north coast of Peru once every 20 years or 30 years." "Again and again torrential rain flattened their temples." "To the Moche, such catastrophes meant the gods were angry." "To placate them and restore order in the world the ultimate sacrifice was called for." "So the Moche were aware of this problem and they created this ritual to counteract the effect of the El Nino and that came as a surprise." "It seems that they conducted a series of ritual combats between selected individuals." "The aim of the combat was to capture the other person almost like a duel." "And the captured person would have been chosen, through this process as the victim for the sacrifice." "But I believe that they were people trained to go to these battles thinking that they would win, but if they lose the battle they had to be sacrificed but they would have willingly offered their soul or their bodies" "to their gods." "So, I would perceive them as champions more than, than victims." "In a volatile and often violent climate the Moche pyramids, it seems were built not to honor their gods but to appease them." "How many more bodies will emerge?" "Whatever the number, it wasn't enough." "After flourishing here for eight centuries" "Moche civilization disappeared." "Even as the Moche temples began to crumble, around 800 A. D another great pyramid civilization was in full swing." "The jungles of Central America are home to the highest concentration of big pyramids anywhere in the world." "Between Mexico and Honduras are the remains of literally hundreds." "And the people who built them haven't vanished." "While their ancient cities no longer flourish the Maya themselves are still here today living off maize just as their ancestors have been doing for thousands of years." "Cutting back the surrounding forests archaeologists continue to find the remains of some of the world's most impressive yet inscrutable monuments." "Who were the ancient Maya?" "And were their pyramids also places of sacrifice, like those of the Moche?" "Like the Egyptians, the Maya built with stone." "And their pyramids, too, such as this one at Chichen Itza in southern Mexico were also linked with other ritual buildings." "But it's the differences that stand out." "A Mayan pyramid is approached not through a closed corridor as in Egypt but from a vast, open plaza." "And with its flights of steps and its summit temple the pyramid looks less like a private tomb and more like a public platform." "A commanding stage, perhaps from which the elite could rule." "As archaeologists piece together the remnants of Maya civilization its achievements continue to amaze." "While the Egyptians wrote on papyrus artifacts unearthed by Carlos Perez show that the Maya had the means to make an equally precious commodity paper." "Here at Chacmultun we've found something unusual." "Tools like this were used by the Maya to make paper from the bark of trees such as this called "Copo" in Maya." "The paper was very important to pre-Hispanic Maya because they use it for writing books for ceremonial things and for keeping accounts." "By at least 300 B. C, the Maya had invented their own unique form of hieroglyphic writing." "It's still only partly deciphered." "They'd also worked out an effiicient way of counting, adding and recording dates using bars and dots." "And by as early as 500 B. C, they'd perfected an accurate 365-day calendar." "They could predict events like eclipses far in advance." "They also had a distinct ritual calendar revolving on a shorter cycle." "Running side by side, their calendars combined to fix the crucial dates in Maya life." "From the tops of their pyramids and even from observatories astrologer-priests tracked the stars and planets." "By timing their rituals for auspicious dates rulers sought to sway the fortunes of their people." "At Chichen Itza, in the shadow of its main pyramid they once gathered for a ritual worthy of ancient Rome." "It was staged combat, Maya style." "A kind of soccer but played for the highest stakes." "Stone panels, once in vivid color adorned the ball court." "On the right, the kneeling loser head chopped off, and serpents spurting from his neck." "To the left, the victorious player grasping his bloody trophy." "Perhaps their victims were heroes but it's hard to be sure." "Of the countless books written by the ancient Maya all but a few were destroyed by Spanish missionaries." "With these works went priceless clues to Maya culture." "But a new theory claims that one fundamental clue might actually lie below every major Mayan pyramid." "So that what we're looking at is just the tip of the iceberg." "Strangely, water is elusive in this jungle." "The region is a limestone plain where rivers, instead of crossing the surface run deep underground." "Irrigation is impossible." "The only year-round sources of water are the occasional caverns that descend into the earth." "To the modern Maya such caverns are still a lifeline and considered sacred." "In the Maya region and far beyond people have had an age-old fixation with caves." "For many, they're still the home of gods." "And to archaeologist Jim Brady it all points downwards." "The spiritual heart of these ancient cultures, he believes was not the pyramid itself but its secret cave." "We know that pyramids represent Earth." "They are called in the Maya area witz, hills, mountains." "They represent the sacred mountain." "And sacred mountains have to have a cave by which you can reach the deities that live inside them." "All Amerindian people have a special appreciation and attachment to Earth as a sacred and animate entity." "Not only does it mean crop fertility but rain is also a terrestrial phenomenon." "Rain is believed to come out of caves up into the sky." "People are still going to caves to pray for rain and for a good harvest." "In each site he checks" "Brady finds a cave under its main pyramid." "But proof of a link comes from places like X ochicalco in central Mexico where caves don't naturally exist." "Here, they had to be made by hand." "This isn't natural." "Everything that you see was constructed." "And considering that the people did not have steel tools it was an enormous undertaking." "The cave extends for over 200 feet through solid rock passing beneath the pyramid complex." "It's dark and damp and filled with bats hardly fit for storage or habitation." "Surely, this vast, man-made cavern had a higher purpose." "The most spectacular thing that marks it as a ritual cave is the skylight entrance in which you can control the light and actually measure the passing of the seasons." "You have the sun marked here on the floor and you're linking Earth and sky the two aspects of the universe." "You're talking about ritual space at the very center of the site." "Probably only the priesthood and the king had access so the rituals of the highest order would be conducted here." "The very word for cave also meant temple in ancient Mayan." "Brady has little doubt that many more temple caves will come to light under pyramids." "A deeper picture of the Central American pyramid is perhaps emerging." "Together with its cave, it embodies the sacred mountain with its source of water the elusive water, that ultimately was the gift of the gods." "So much for the underground." "What stands above ground has a far more earthly purpose." "It's something that Jim Brady can grasp more easily from the air." "For it wasn't just the gods whom the ancient rulers sought to impress with their pyramid temples and their shows of human sacrifice." "From Egypt to Mexico from China to Peru pyramids were meant to cow the masses." "Bountiful crops mean a burgeoning population." "And as numbers grow, so does the need for social control." "That must have been true here at Teotihuacan in central Mexico the largest pyramid city in the Americas." "What you can see here and you can't appreciate out on the ground is the enormous size of this city." "It stretched for miles." "There were probably between a 100,000 and a quarter of a million people living here at its height at 700 A.D." "In Europe at that time nothing could compare." "The centerpiece was the colossal Pyramid of the Sun its base equal to that of the Great Pyramid in Egypt." "This was propaganda, plain and simple a reminder to the masses of who was really in charge." "The pyramids that we see here are a symbol of the power of both God and the political entity that brought 'em into being." "They combine political and religious power." "We're used to having those two separated but in pre-industrial societies there was a conscious effort to combine them both and the pyramid stands as the pre-eminent symbol of this fusion." "Religion and rulership church and state." "The two went together and were symbolized by this single massive edifice at the core of the community." "Egypt's pyramids had certainly shown who was boss." "But did the Egyptians also practice human sacrifice?" "Until recently, we didn't have a definitive answer." "Now, thanks to some recent archaeological excavations at the site of Abydos the answer apparently is yes but for a very very brief period of time." "A time at the very beginning of Egyptian civilization lasting perhaps 300 years when the servants of dead kings were it seems, sent with their masters into the next world." "What's more remarkable is that the practice was abandoned never to return." "But of course, water here was never a problem." "The River Nile was one of the calmest most predictable rivers on earth." "Every summer it would flood but gently, not destructively providing water for irrigation for crops, for people and animals." "It also brought with it every year fresh silt that covered the lands of ancient Egypt making this one of the richest agricultural zones on the face of the earth." "Travelers who came here were amazed." "According to the ancient Greeks the Egyptians had little to do." "Year in and year out the living was easy." "There were no major worries." "And perhaps that's the reason there was no human sacrifice." "There was nothing hanging over the head of an ancient Egyptian that required him, in sheer terror to commit the ultimate sacrifice to try and plead with his gods to feed him, feed his children and keep them alive." "Blessed with such a bountiful land relations with the gods were always good." "But nothing could be taken for granted." "To maintain this abundance clear communications with the gods were vital." "And these could only be passed through a divine king." "Now when pharaoh died you can see a major problem." "This lack of communication could mean the sun would no longer rise and set the river wouldn't rise and fall the moon wouldn't wax and wane." "We were in deep doo-doo." "It was essential the dead king take his rightful place with the gods to speak on behalf of humankind." "And for a 1,000 years the key to his safe transport was the mighty pyramid." "The building of a pyramid may have been an economically enormous undertaking but when you stop and think of the alternative to continuity and human existence, it's a pretty small price to pay." "But the pyramid story has a final and bloody, chapter." "Around 1250 a nomadic tribe called the Mexica moved south into the Valley of Mexico." "More widely known as the Aztecs they were soon feared by the surrounding tribes." "Though outnumbered at first they settled the land and prospered." "Before long, these corn farmers were growing into a terrifying superpower." "By 1500 the Aztecs had conquered lands stretching from the Pacific to the Gulf of Mexico." "Their capital Tenochtitlan was one of the largest cities in the world." "Spanish eyewitness accounts describe a magnificent sacred precinct a place of breathtaking beauty but caked with sacrificial blood." "Beside the double pyramid stood one of the holiest of Aztec temples the House of Eagles." "Four and a half centuries later scientists are looking more closely at its floors and benches." "How accurate were those eye witness accounts?" "Hundreds of samples have been gathered and analyzed for blood and other substances." "The findings, like Aztec religious sculpture point to a grim and fearful relationship with the gods." "By carefully mapping their results the scientists can show us exactly where burning incense dripped onto the floor and where human blood soaked in." "Artwork shows that the blood was poured from bowls over the Aztec god of death." "It was blood from ritual self-mutilation, devoutly offered." "But the Aztec gods also demanded sacrifice." "And they had an unquenchable appetite for human hearts." "This was the fate of countless captives to have their heart chopped out on an Aztec pyramid." "But strangely, the destruction of this last surviving pyramid culture was foretold in the Aztecs' own prophecies." "Dead on cue, the Spanish arrived in 1519." "Fighting from horseback with steel and shot, the conquistadors swiftly crushed Aztec civilization and buried it under their own city." "And with this savage blow pyramids faded into history."