Criss-crossing the valleys of Bolivia, hundreds of metres above the ground, is a network of makeshift cables. Clinging onto these cables, coca growers whizz across the mountains, transporting their harvest. Should they slip or the aged cables snap, they face certain death. Once they’ve reached the other side of the mountain, the danger doesn’t end. The coca then has to be transported along the ’Camino de la Muerte’, or Highway of Death’. It’s the only route connecting La Paz, Bolivia’s administrative capital, with the Amazon Basin. And it’s officially the most dangerous road in the world.