44. Arenal Volcano National Park ( Costa Rica )

Arenal Volcano National Park is a Costa Rican national park in the central part of the country, forming the Arenal Tilaran Conservation Area. The park encompasses the Arenal Volcano, the most active in the country, which had previously been believed to be dormant until a major eruption in 1968. It neighbours Lake Arenal, which is the site of the country's largest hydroelectricity project, the Lake Arenal Dam.

The park also contains a second volcano, Chato, whose crater contains a lagoon. It is also called Cerro Chato (literally Mount Chato) as it has been inactive for around 3500 years–coinciding with the creation and growth of Arenal itself. The site has accommodation in the form of the Arenal Observatory Lodge and also the Museum of Vulcanicity, as well as a ranger station.

The park lies within the 2,040 square kilometres (790 sq mi) Arenal Tilaran Conservation Area, protecting eight of Costa Rica's 12 life zones and 16 protected reserves in the region between the Guanacaste and Tilarán mountain ranges, and including Lake Arenal. The park is most directly accessed from La Fortuna, but is also easily accessed via Tilarán and the north shore of Lake Arenal.