Irazú is an active volcano in Costa Rica, situated in the Cordillera Central close to the city of Cartago. Its name is believed to be a corruption of Iztarú, which was the name of an indigenous village on the flanks of the volcano. Irazú has erupted frequently in historical times – at least 23 times since its first well-recorded eruption in 1723. Its most recent eruption began in 1963 and continued until 1965. It began on the day US President John F. Kennedy began a state visit to Costa Rica, and showered the capital San José and much of the central highlands of Costa Rica with ash.
Since the 1963-5 eruption, the volcano has been dormant, although frequent earthquake swarms show that magma is still moving about beneath the volcano. In 1994 a small phreatic eruption occurred, caused by heavy rains destabilising part of the volcano’s flank, resulting in rapid decompression of a shallow hydrothermal system.
The volcano’s summit has several craters, one of which contains a green crater lake of variable depth. It is the highest active volcano in Costa Rica. It is easily visited from San José, with a road leading right up to the summit craters and a daily bus service to the top. It is thus a popular tourist spot.