Colca Canyon

English Wikipedia gives a depth of about 3,270 metres and a length of about 70 kilometres in its introduction, but another section gives 100 kilometres and 3,400 metres, and the Spanish article cites a 2005 Polish-led survey reporting up to 4,160 metres near Huambo, so published figures are inconsistent and best read as approximate. The articles agree that it is among the deepest canyons in the world. A Polish expedition made the first descent of the river below Cabanaconde in 1981, and the Guinness Book of Records recognised the claim in 1984. The canyon base lies at about 2,000 metres and the rim at roughly 3,000 to 4,000 metres. Chivay is the midpoint of the valley, and Cabanaconde lies downstream. The snow-capped extinct volcano Ampato, 6,288 metres high, rises about 24 kilometres southeast of Cabanaconde.

The Spanish article says the canyon began to form roughly 10 million years ago, with its present shape probably dating to the last million years. It attributes the deepening to the rise of the Andes, glacial retreat in the Quaternary and erosion by the Colca River, and says volcanic deposits from Sabancaya and Hualca Hualca once dammed the river, creating a lake from Madrigal to Yanque, before the dam broke and the river cut deeper.

Pre-Inca inhabitants included the Quechua-speaking Cabanas and the Aymara-speaking Collaguas, according to English Wikipedia, and the name Colca is said to come from the names of these two groups. The Incas arrived around 1320 and are said to have established control mainly through marriage rather than war. The Spanish arrived in 1540 under Gonzalo Pizarro, and in the 1570s Viceroy Francisco de Toledo ordered residents into central settlements that remain the valley's main towns. Franciscan missionaries built the first chapel in 1565 and the first church in 1569. The Spanish article describes the valley's churches as a mestizo Baroque style with influences from Arequipa and Cusco, some built entirely of sillar.

Pre-Inca andenes, or stepped terraces, are still farmed today. No passable road linked Arequipa and Chivay until the 1940s, and later roads in the 1970s and 1980s were tied to the Majes Hydroelectric Project, which diverts river water for irrigation. The valley is also known for baby alpaca knitwear and the embroidery that decorates skirts and hats. Caves in the valley hold rock paintings and carvings said to be more than 6,000 to 7,000 years old.

The Andean condor is the main attraction, and Cruz del Condor is a popular viewpoint where the canyon floor is about 1,200 metres below the rim. Other wildlife includes the giant hummingbird, Andean goose, Chilean flamingo, vicuna and vizcacha. Spanish Wikipedia notes that residents say condors were more frequent in the past.

The La Calera hot springs are at Chivay, with other springs through the valley. Archaeological sites include the Caves of Mollepunko, with rock art said to depict alpaca domestication, and the reconstructed hilltop Fortaleza de Chimpa. The Wititi dance festival in Chivay is recognised as Peruvian cultural heritage. Because the journey from Arequipa crosses high passes, a private guided visit with a driver lets the group plan stops and condor viewing around the conditions of the day.