Reserva Natural Laguna de Apoyo, Protected volcanic lake area in Masaya and Granada, Nicaragua

The Reserva Natural Laguna de Apoyo protects Laguna de Apoyo, an endorheic lake filling the caldera of an extinct volcano between the departments of Masaya and Granada. The roughly round lake measures 6.6 km across, covers 19.44 km² and reaches 175 m deep, with a drainage basin of 38 km². Steep slopes of tropical dry forest ring the water.

The lake formed about 23,000 years ago when the Pre-Apoyo Volcano erupted and left the crater now holding the water. Indigenous people fished its waters and carved petroglyphs near the shore, and two indigenous cemeteries lie nearby, though no settlement remains have been found inside the crater.

Indigenous people fished in the lake and carved petroglyphs at spots near the shore in honour of their gods. Two indigenous cemeteries confirm the site's sacred role, though no settlement remains have been found inside the crater, only outside it.

Visitors can swim, scuba dive, and kayak here, with access via an unpaved road from kilometer 37 of the Masaya-Granada highway. It is wise to bring sturdy shoes since paths to the water can be uneven, and the easiest access occurs during drier months.

The lake holds six endemic cichlid species of the genus Amphilophus found nowhere else; the arrow cichlid was described in 1976, three more in 2008 and two in 2010 by a team from the FUNDECI/GAIA station on the shore. Tilapia introduced by humans now threatens them.