El Altar or Capac Urcu (possibly from Kichwa kapak principal, great, important / magnificence, urku mountain) is an extinct volcano on the western side of Sangay National Park in Ecuador, south of Quito, with a highest point of . 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.
El Altar consists of a large stratovolcano of Pliocene-Pleistocene age with a caldera breached to the west. Inca legends report that the top of El 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 form a horseshoe-shaped ridge about across, surrounding a central basin that contains a crater lake at about , known as Laguna Collanes or Laguna Amarilla.
El Altar is perhaps the most technically demanding climb in Ecuador. The route to the El Obispo summit is graded D+. 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 to enter the Sangay park. About 4âÂÂ7 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. The refuge has many beds, and a kitchen. The hike to the lake is another 1.5h - 2 hours from the refuge across a valley and up a steep hill.
The nine peaks of El Altar, starting with the highest summit on the south side and proceeding counterclockwise: