The Colca River flows through the Colca Canyon in southern Peru, a gorge that Peruvians claim is the world’s deepest. The canyon measures nearly 3,400 metres (11,155 feet) from the bottom of the river to the mountain tops above. Agricultural terraces in the canyon, some of them built 2,500 years ago, are used today by Native Americans who live along the river. Andean condors nest near the Colca, and archaeological ruins are scattered throughout the canyon.