Santa Ana Volcano, Active stratovolcano in Santa Ana, El Salvador

Santa Ana Volcano is an active stratovolcano in Santa Ana Department, El Salvador. Its summit holds several nested craters, with the innermost containing a turquoise acid lake colored by volcanic gases.

A large collapse reshaped the volcano during the late Pleistocene period, sending debris flows toward the coast. The most recent major eruption occurred in October 2005, prompting evacuations in nearby communities.

The name Ilamatepec comes from Nawat and means "the hill of the old woman". In 1892 Santiago Barberena called it Amatepeque, then corrected himself in 1905 to Ilamatepec; historian Jorge Lardé y Larín noted no authentic document records any of these indigenous names. During the colonial era the volcano was also called Volcán de los Izalcos, Volcán de Fuego and Volcán de Sonsonate.

The hike begins at Cerro Verde National Park and takes about two hours over a steep trail with rocky sections. Visitors should start early in the morning, as fog often rolls in during the afternoon and obscures views of the crater lake.

Sulfur fumes from the crater lake stain rocks along the rim in bright yellow and orange, creating patterns that resemble molten metal in some spots. The water temperature fluctuates with volcanic activity and can rise noticeably during periods of increased gas release.