Take a behind the scenes look to see how we fared when filming in the inhospitable conditions of the Giant Crystal Cave. Ian Stewart gives his personal account in this exclusive interview from 'How Earth Made Us'.
Watch the interview on our official BBC web page
Read my personal account and see more images here.
Watch a preview clip from the sequence here
'How Earth Made Us' starts on the 19th January, 9pm on BBCTwo.
In the first programme Iain explores the relationship between the deep Earth and the development of human civilisation. He visits an extraordinary crystal cave in Mexico, drops down a hole in the Iranian desert and crawls through seven-thousand-year-old tunnels in Israel.
His exploration reveals that throughout history, our ancestors were strangely drawn to fault line, areas which connect the surface with the deep interior of the planet. These fault lines gave access to important resources, but also brought with them great danger.
Presenter, Iain Stewart inside the remarkable Naica crystal cave. With temperatures reaching 50 degrees Celsius and a 100% humidity level, the caves prove to be a very hostile environment (copyright BBC)