Chato Volcano, sometimes called "Cerro Chato" (Spanish for "Flat Hill"), is an inactive volcano in northwestern Costa Rica northwest of San José, in the

province A province is almost always an administrative division within a country or state. The term derives from the ancient Roman '' provincia'', which was the major territorial and administrative unit of the Roman Empire's territorial possessions ou ...

Alajuela Alajuela () is a district in the Alajuela canton of the Alajuela Province of Costa Rica. As the seat of the Municipality of Alajuela canton, it is awarded the status of city. By virtue of being the city of the first canton of the province, it i ...

, canton of San Carlos, and

district A district is a type of administrative division that, in some countries, is managed by the local government. Across the world, areas known as "districts" vary greatly in size, spanning regions or county, counties, several municipality, municipa ...

of La Fortuna. It is southeast of the nearby

Arenal Volcano Arenal Volcano ( es, Volcán Arenal) is an active andesitic stratovolcano in north-western Costa Rica around northwest of San José, in the province of Alajuela, canton of San Carlos, and district of La Fortuna. The Arenal volcano measures ...

. Cerro Chato is believed to have first erupted 38,000 years ago during the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

period and last erupted about 3,500 years ago. One of the lava flows is now the route for La Fortuna Waterfall. The hill has two peaks, named Chatito ("little Chato") and Espina ("thorn"). A crater about wide is filled with green water, making the Laguna Cerro Chato. Arenal Volcano with cattle in foreground

Arenal Volcano with cattle in foreground

Hiking

The Costa Rican government has closed the trail to Cerro Chato making it illegal to climb. This law was passed in 1998 but was not enforced until 2017, encouraging hikers, tour operators and business owners to sell this attraction and tour. When it was open it was considered a difficult hike and only recommended for hikers of good physical condition. When it rains, the path becomes muddy and can make it even more treacherous, especially when descending into the crater itself. The environmental damage the illegal hiking has created is the main cause of the closure.

References

* Profile of Chato Volcano at Costa Rica's Seismic National Network
Basic limnology of fifty-one lakes in Costa Rica (contains some information on Laguna Cerro Chato)
* {{Central American volcanoes Stratovolcanoes of Costa Rica Mountains of Costa Rica Inactive volcanoes Pleistocene stratovolcanoes Geography of Alajuela Province