El Altar Volcano

El Altar, Kapak Urku in Kichwa, is what remains of a much larger volcano that collapsed catastrophically, leaving a horseshoe of nine jagged peaks around an amphitheatre with a turquoise crater lake, the Laguna Amarilla, at its floor, fed by ice falling off the summits. Climbers consider its peaks among the hardest in Ecuador; walkers come instead for the trek to the rim viewpoint, a route from Candelaria through the Collanes plain that is famously, relentlessly muddy and usually takes two days with a night camping or in a basic refuge. When the cloud lifts, the ring of broken summits above the lake is the finest mountain view in the country to many who have made it.

What you actually see

• The horseshoe of nine peaks - the broken ring of a collapsed volcano.
• Laguna Amarilla - the turquoise lake in the amphitheatre floor.
• The Collanes plain - the boggy flat below the crater.
• Ice falling into the lake - the glaciers feeding the water.

When to go

June to September, though it rains here in every season. Two to three days. Horses can be hired at Candelaria to carry loads. Waterproof boots are not optional.

Honest expectations

The trail is mud, deep and continuous, and people underestimate it badly. Cloud hides the crater on most days, and many trekkers see nothing. The refuge is very basic and cold. The peaks themselves are for experienced alpinists only.

Nearby

Riobamba is west; Sangay park continues south.