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. In and around the park are various lodges and hotels, some with their own hot springs, and others focused on the wildlife of the area. Within the national park are the Museum of Vulcanicity and 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.