"Lake Titicaca is one of the world’s great sights. A vast inland sea improbably located in the sky. If it were in Europe, its surface would be above all the highest peaks in Switzerland and Austria, and its area would measure more than twice the size of all their lakes combined. ... ... If Titicaca was never a serious contender as the source of the Amazon (it’s in the mountains to the north), it is the cultural heart for Indigenous people."