Apoyo is a lake filled caldera immediately SE of Masaya volcano and near Granada town in Nicaragua. The scenic caldera is 7 km wide and surrounded by steep walls rising 100 m at the eastern rim and 500 m at the west. The surface of Laguna de Apoyo is only 78 m above sea level. Measured from the bottom of the lake, the caldera is about 600 m deep.

Apoyo belongs to a large silicic volcanic center that first built a basaltic-to-andesitic shield volcano and later small rhyodacitic lava domes. This edifice collapsed during 2 major dacitic explosive eruptions, which have been radiocarbon dated at about 23,000 years ago.

Post-caldera ring-fracture eruptions of uncertain age produced lava flows below the scalloped caldera rim. The younger slightly arcuate, N-S-trending La Joya fracture system that cuts the eastern flank of the caldera only 2 km east of the caldera rim is a regional fissure system structurally unrelated to Apoyo caldera.



(Source: adapted from Smithsonian / GVP volcano information