Discover Lake Atitlán

Lake Atitlán fills a volcanic caldera created by the Los Chocoyos eruption approximately 85,000 years ago—one of the largest volcanic events in the geological record of the Americas. The eruption ejected enough ash to leave a detectable layer in sediment cores from the Gulf of Mexico and as far north as Florida. The caldera slowly filled with water, creating a lake at 1,562 meters above sea level. Three post-caldera stratovolcanoes grew inside and on the rim: Volcán San Pedro (2,995m) on the western shore—extinct for ~40,000 years; Volcán Tolimán (3,158m) on the southern rim—active but without a recorded eruption; and Volcán Atitlán (3,537m)—still active, last significant eruption 1853.

The lake is the deepest in Central America at 340 meters and has no surface outlet—water escapes only through underground caldera fissures. A magnitude 7.5 earthquake in February 1976 cracked the lake bed and caused the water level to drop two meters in one month. The lake’s extraordinary blue color and mirror-like quality made German explorer Alexander von Humboldt describe it as “the most beautiful lake in the world,” and Aldous Huxley wrote that Atitlán is “Lake Como with additional embellishments of several immense volcanoes.”