Colca Canyon is a canyon of the Colca River in southern Peru. It is located about 100 miles (160 kilometers) northwest of Arequipa. It is more than twice as deep as the Grand Canyon in the United States at 4,160 m., and it is promoted as the "world's deepest canyon," although the canyon's walls are not as vertical as those of the Grand Canyon. The Colca Valley is a colorful Andean valley with towns founded in Spanish colonial times, and still inhabited by people of the Collaguas and the Cabanas cultures. The local people still maintain ancestral traditions and continue to cultivate the pre-Inca stepped terraces. The name Colca refers to small granaries of mud and stone, built into the cliffs in the valley and canyon. These repositories were used in Inca and pre-Inca times to store food, such as potatoes, quinoa, and other Andean crops. They were also used as tombs for important people.