Sumaco, Stratovolcano in Napo Province, Ecuador.

Sumaco is a stratovolcano in Napo Province that rises to 3,990 meters and features a wide crater at its summit. Dense cloud forest covers the slopes, creating a wet and green environment that changes dramatically with altitude.

Sumaco's only documented historical eruption occurred around 1895, with an uncertainty of about thirty years. The volcano stands apart from Ecuador's main volcanic axis, and its basanite and phonolitic rocks differ from the andesitic composition of most Andean volcanoes.

The volcano lies in Napo Province, where Kichwa communities of the Quijos and Cosanga river valleys hold the mountain as part of their territory. Its name comes from the Quechua Sumaku. The lower slopes are farmed and the forest above is used for hunting and gathering.

Climbing this peak requires experienced local guides and proper equipment, as weather changes rapidly and visibility is often limited. An early start and planning around the best climbing season are essential for safety.

The mountain is home to a rare frog species called Pristimantis ernesti, found nowhere else except at the summit. This tiny amphibian thrives in the misty conditions at the very top of this isolated peak.