El Altar

El Altar or Kapak Urku (Kichwa kapak principal, great, important / magnificence, urku mountain, "sublime mountain", hispanicized Capac Urcu, Cápac Urcu) is an extinct volcano on the western side of Sangay National Park in Ecuador, 170 km south of Quito. Spaniards named it so because it resembled two nuns and four friars listening to a bishop around a church altar. In older English sources it is also called The Altar.

Geology
The mountain consists of a large stratovolcano of Pliocene-Pleistocene age with a caldera breached to the west. Inca legends report that the top of Altar collapsed after seven years of activity in about 1460, but the caldera is considered to be much older than this by geologists. Nine major peaks over 5,000 metres (16,400 ft) form a horseshoe-shaped ridge about 3 kilometres (1.9 mi) across, surrounding a central basin that contains a crater lake at about 4,200 m (13,800 ft), known as Laguna Collanes or Laguna Amarilla.

Access and recreation
El Altar is perhaps the most technically demanding climb in Ecuador. December through February are the best months to attempt an ascent. Much more accessible is the hike to the lake within the caldera of the mountain. From Riobamba, one takes a bus for about an hour to Candelaria and then checks in at the ranger station, where nationals pay $2 and foreigners $10 to enter the Sangay park. About 4–7 hours of an extremely muddy trail (knee-high rubber boots are recommended) leaves one at the refuge belonging to Hacienda Releche, which can be rented for $12/night. The refuge has many beds, a kitchen, and even hot water. To hike to the lake is another 2 hours from the refuge across a valley and up a steep hill.

List of peaks
The nine peaks of El Altar, starting with the highest summit on the south side and proceeding counterclockwise: