Zapatera volcano is a low shield volcano forming a 7 x 10 km wide densely forested island on the western part of Lake Nicaragua. The island is located opposite Mombacho volcano and separated by a narrow strait from the mainland. Zapatera volcano is believed to be still active, but the age of its last activity is unknown. Zapatera island contains some of the most important archaeological sites in Nicaragua and is part of Zapatera Archipelago National Park, one of 78 protected areas of Nicaragua.

The island is cut by a series of NE-trending faults that continue into Lake Nicaragua. Zapatera volcano contains a small, roughly circular 2-km-wide caldera (El Llano) occupied by a the conical 305-m-high Cerro El Llano lava dome. Other lava domes are found on the southern and NE flanks, as well as many tuff rings and maars on the northern and western sides including the well-preserved Laguna de Zapatera on the NW flank.