Izalco (in Nawat: Itzalku) is a municipality in the Sonsonate department of El Salvador.Volcan Izalco is an icon of the country of El Salvador, a very young Volcano on the flank of Santa Ana volcano. From when it was born in 1770 until 1966, it was in almost continuous eruption and was known as the "lighthouse of the Pacific." Since then it has been nearly inactive.