Masaya is a shield volcano located 20 km south of Managua, Nicaragua. It is Nicaragua’s first and largest National Park, and one of 78 protected areas of Nicaragua. The volcanic complex is composed of a nested set of calderas and craters, the largest of which is Las Sierras shield volcano and caldera. Within this caldera lies Masaya Volcano sensu stricto, a shallow shield volcano composed of basaltic lavas and tephras. This hosts Masaya caldera, formed 2500 years ago by an 8-km³ basaltic ignimbrite eruption. Inside this caldera a new basaltic complex has grown from eruptions mainly on a semi-circular set of vents that include the Masaya and Nindiri cones. The latter host the pit craters of Masaya, Santiago, Nindiri and San Pedro. Observations in the walls of the pit craters indicate that there have been several episodes of cone and pit crater formation.