Volcanoes

Costa Rica is home to majestic volcanoes such as Arenal, Poás, Irazú, Turrialba, and Rincon de la Vieja that define the impressive mountainous landscapes of this beautiful country. Visiting Rio Celeste? You are actually going to visit the Tenorio Volcano National Park. These volcanic formations result from the tectonic activity, specifically the subduction of the Cocos Plate beneath the Caribbean Plate. Costa Rica is part of the Pacific Ring of Fire, a horseshoe-shaped zone known for its intense volcanic activity and frequent earthquakes, encircling the Pacific Ocean basin. This geological feature arises from the tectonic movements of the Earth's plates. In Costa Rica, the Ring of Fire manifests through its numerous active and dormant volcanoes, as well as geothermal activity that shapes the country's landscapes. 

The Observatorio Vulcanológico y Sismológico de Costa Rica de la Universidad Nacional (OVSICORI-UNA), or translated the Volcanological and Seismological Observatory of Costa Rica, is a scientific institution dedicated to monitoring and studying the geological activity of Costa Rica. They play a crucial role in hazard mitigation efforts by providing continuous surveillance of its numerous volcanoes and seismic activity. They do this through a network of advanced monitoring stations collecting real-time data on things like seismicity, ground deformation, and gas emissions. With this data, they continuously assess and communicate the activity levels of Costa Rica's volcanoes, contributing to public safety and scientific understanding. They frequently update the status of the active volcanoes on their website: Actividad volcánica. As you can see in the example (dated April 2025) below, there are four levels to indicate the activity of a volcano.

Poás Volcano National Park, located north of San José, is a popular and accessible destination centered around the active Poás Volcano, which stands at 2,700 meters (8,850 feet) and boasts a large, impressive crater. Beyond the main crater, the park offers a scenic hiking trail to Laguna Botos, an older, tranquil crater lake. Visitors must purchase tickets online for park access; both the main crater and the Laguna Botos trail are easily reachable from the parking lot, with the latter offering a glimpse of the volcano's unique vegetation. Explore the North Central Valley where Poás is located.

The volcano's ongoing activity is evident in its hot, acidic crater lagoon, which acts as a geyser, occasionally producing small eruptions. Poás has a history of significant phreatic (steam-driven) eruptions. Notable past events include heightened activity in 1953-1954 with lava extrusion and ashfall, and large phreatic eruptions in 1989-1990. Intense phreatic eruptions in 2017 led to the temporary closure of the park and most recently again in 2025. 

East of San José, near the city Cartago, Irazú Volcano National Park boasts Costa Rica's highest volcano, Irazú, at 3,432 meters (11,260 feet). Its summit offers impressive crater views and, on clear days, a glimpse of both Caribbean and Pacific coasts, though the high-altitude weather is often cold and foggy. Beyond the main craters, the park's Prussia sector provides forested hiking trails and a viewpoint towards Turrialba volcano. Explore the South Central Valley where Irazú is located.

Irazú also has a significant eruptive history, including records back to the year 1723 with the "Diego de la Haya" eruption, thereafter a prolonged period of activity from 1917-1920, and the impactful 1963-1965 period of activity with an eruption which caused extensive ashfall over San José and the Central Valley. Did you know that Cartago used to be the capital of Costa Rica? Due to a series of earthquakes in the 19th century combined with political factors, the more strategically and less vulnarable city of San José became the new capital.

Turrialba Volcano National Park, located near Paraíso and Turrialba, is a protected area rich in biodiversity and offering stunning views, dominated by the active Turrialba Volcano. Standing at 3,340 meters (10,958 feet), the volcano provides spectacular panoramas, potentially extending to the Caribbean coast and the Talamanca mountain range. It is said that the name Turrialba translates to Turri-Alba meaning something like white tower or white column. Explore the South Central Valley where Turrialba is located.

Turrialba has a history of significant eruptions. A major active period from 1864-1868 involved large ash explosions and incandescent rockfalls, blanketing the Central Valley with ash. The early to mid-20th century saw intermittent activity, but a dramatic increase occurred from 2014-2017, with numerous large ash eruptions forcing the closure of both Juan Santamaría International Airport and the National Park for safety. Since late 2020/early 2021, the park has reopened, allowing guided morning hikes to the craters.

The Arenal Volcano is a popular tourist destination, particularly around the town of La Fortuna, from where you can see this impressive conical shaped giant. The region surrounding Arenal is rich in natural beauty, including hot springs, waterfalls, and diverse wildlife. The Arenal Volcano National Park, along with private reserves like Arenal 1968 offer numerous hiking trails that traverse old lava fields and secondary forests, providing views of the volcano and the surrounding landscape.  You can not go up the volcano itself. Explore the Northern Zone where Arenal is located.

Arenal Volcano was famously active for decades, with its most significant eruptive period lasting from 1968 until 2010. The most important eruption occurred on July 29, 1968, when the volcano violently erupted after hundreds of years of dormancy and devastated the towns of Pueblo Nuevo and Tabacón. Afterward, during a long period of activity, it was possible to see fiery-red lava streams at night. However, since 2010, the volcano has been dormant.