Lake Amatitlán, Volcanic crater lake near Guatemala City, Guatemala

Lake Amatitlán is a volcanic crater lake near Guatemala City with two distinct basins connected by a narrow channel, stretching about 11 kilometers long and 3 kilometers wide. The lake sits at about 1,186 meters elevation in the region's highland setting.

Lake Amatitlán occupies the Amatitlán caldera in Guatemala's central highlands, formed by tecto-volcanic movements linked to the Pacaya, Agua, Fuego and Acatenango volcanoes during the Quaternary. In pre-Columbian times it supplied water and food to the Pocomam communities settled around its shores. A dam carrying a former railway, known as El Relleno, was built at the narrowest point and divides the lake into two basins.

Amatitlán is a Nahuatl agglutinated toponym: amatl, the amate tree (Ficus glabrata), loses its final -tl and joins titlan, "between" or "surrounded by", so the name means "between the amates" or "surrounded by amates". Before the Spanish arrival the lake supplied water and food to the Pocomam communities settled around its shores.

The lake is surrounded by four municipalities and serves water supply, irrigation, and industrial needs while supporting fishing communities around it. Visitors can access the shoreline from various points, though conditions vary depending on location and season.

A dam topped by a railway was built at the lake's narrowest point, called El Relleno, dividing it into a north-western and a south-eastern basin with different physical, chemical and biological characteristics. The barrier is a visible feature of the shoreline.