The Miravalles Volcano is an andesitic stratovolcano in Costa Rica. The caldera was formed during several major explosive eruptions that produced voluminous dacitic-rhyolitic pyroclastic flows between about 1.5 and 0.6 million years ago. The only reported historical eruptive activity was a small steam explosion on the SW flank in 1946. High heat flow remains, and Miravalles is the site of the largest developed geothermal field in Costa Rica.
The Miravalles Volcano reaches an elevation of 6,653 feet (2,023 m) and is the highest mountain in the Guanacaste Mountains. The heat from the volcano also helps power a geothermal energy plant at Las Hornillas, which is run by the Institute of Electricity