El Altar or Capac Urcu (possibly from Kichwa kapak principal, great, important / magnificence, urku mountain)[3][4] is an extinct volcano on the western side of Sangay National Park in Ecuador, 170 km (110 mi) south of Quito, with a highest point of 5,319 m (17,451 ft).

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.

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 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.

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