Overview: The longest chain of mountains in the world at 7200km, the Andes run the length of western South America and dictate the climate for the whole continent. From the northern coasts of Venezuela to the tip of Tierra del Fuego in Chile, they include some of the highest peaks outside the Himalayas. Live volcanoes punctuate the range, and form part of the Pacific Rim of Fire. This episode explores how life has managed to exist in this high altitude world of extremes.