Numerous lakes of volcanic origin are found in the interior highlands; many of these lakes are surrounded by mountains and have high, steep banks. The largest lake, the Lago de Ilopango, lies just to the east of the capital. Other large lakes include the Lago de Coatepeque in the west and the Lago de Güija on the Guatemalan border. The Cerron Grande Dam on the Rio Lempa has created a large reservoir, the Embalse Cerron Grande, in northern El Salvador.
Numerous lakes of volcanic origin are found in the interior highlands; ?many of these lakes are surrounded by mountains and have high, steep banks. The largest lake, the Lago de Ilopango, lies just to the east of the capital. Other large lakes include the Lago de Coatepeque in the west and the Lago de Güija on the Guatemalan border. The Cerron Grande Dam on the Rio Lempa has created a large reservoir, the Embalse Cerron Grande, in northern El Salvador.