Originally published 01/22/2013
THE small steel door in the mountainside is the same shade of green as the lush vegetation surrounding us. Before we enter, my guide, prehistorian Roberto Ontañón Peredo, asks if I would like him to switch on the main lights. I decide to discover this place the way my ancestors would have done, with just a small bubble of light. As the door closes behind us, we flick on our flashlights and their beams pick out the irregular walls of the El Castillo cave. What strikes me first is the size of the cavern: I've been in churches that could fit in here.This cave, in northern Spain, was regularly visited by our prehistoric ancestors for tens of thousands of years, and as I follow Roberto inside, I see some of the extraordinary paintings they left behind. Red deer, bison and mammoths hide in the shadows, their outlines eerily materialising ...