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 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 refuge has many beds, and a kitchen. To hike to the lake is another 1.5h - 2 hours from the refuge across a valley and up a steep hill.