"This part of Huelva gets a lot of rain." "It rains a lot, so the aquifers are full of water." "The Romans had to use waterwheels and Archimedes' screws to keep the line dry." "This is repeated throughout History." "They set up pumps to take the waterout." "When they abandoned the mine the water table level rose and the watersurfaced as you can see in this gallery." "This water looks clear, but can you notice the smell?" "No..." "Sure, a little bit." "Normal water doesn't smell." "But this one does." "It smells like iron." "This water... is the same as the water in Rio Tinto." "It contains 6 to 8 grams of heavy metals per litre of water, and a pH of 2.2." "In other words, this water is totally poisoned by heavy metals." "Do you think it is possible... for life to survive in this water?" " No, no..." " No?" " Look at the water..." " It's green...!" "She said it." "She looked at the water:" "it's green, of course there's life." "It's clearly visible." "This is biodiversity." "These are microorganisms in the form of microscopic acidophiles." "We can see them because they are combining." "They are forming colonies." "If they weren't... they would only be visible with a microscope." "There are also colonies of euglena which are the greener areas you can see on the side." "They are photosynthetic frotitas." "These microorganisms use the Rio Tinto poison - the heavy metals - as an energy source." "Why is this water clear... while the water in Rio Tinto is totally red?" "And the water we will see in the aquifer is red too." "What could be the difference between clear water... and reddish water?" "Whatever is at the bottom..." "No." "The only difference..." "The only difference is the type of oxide." "Run, everybody's leaving!"