The quick answer
Arenal is not erupting, and has not erupted since December 2010. The eruptive period that began with the catastrophic eruption of 1968 declined through the 2000s and stopped; the volcano has been in its longest quiet phase since then, with weak gas and steam emissions from the summit and nothing else. Tour marketing across the industry still implies nightly lava, and it is not there.
That is not a reason to skip it. La Fortuna is the best-equipped base in Costa Rica and the mountain is the reason everything around it exists.
What happened, and when
Arenal was believed dormant until July 1968, when it erupted violently without meaningful warning, destroyed two villages on its western flank and killed dozens of people. What followed was more than four decades of near-continuous activity: slow lava effusion, explosions at the summit, and occasional pyroclastic flows, which is what made the mountain famous and what built the tourism economy at its foot.
That period ended in December 2010. The Smithsonian Institution’s Global Volcanism Program, drawing on reports from Costa Rica’s own volcanological observatory OVSICORI-UNA, records the end of the eruption and the quiet that has held since. The volcano remains active in the geological sense and is monitored continuously. It is simply not putting on a show.
What you will see
A near-perfect cone, when the weather allows. Arenal makes its own cloud and is frequently hidden, particularly in the afternoon and particularly in the green season. Mornings are the best chance. Plan a stay of two nights or more rather than one, so that a clouded day is not the only day.
Around the mountain there is more to do than almost anywhere else in the country: hanging bridges through the forest canopy, the old lava fields, La Fortuna waterfall at the foot of a long staircase, Lake Arenal, and the hot springs that the volcano’s heat feeds.
The hot springs
Geothermally heated water is the reason many people come. The options run from large landscaped resorts to modest local pools to a free stretch of hot river near the entrance to one of the resorts. They are genuinely relaxing after a day of walking, and they are the one thing here that does not depend on the weather.
Visiting the park
Arenal Volcano National Park is administered by SINAC, and access is controlled. The summit is not climbable and the trails run through the forest and over old lava on the lower flanks. Opening arrangements, capacity and any restricted sectors are set by SINAC and can change, so check current arrangements rather than relying on a tour listing.
⚠ It is not a World Heritage Site
Costa Rica has four properties inscribed on the UNESCO World Heritage List: the Area de Conservación Guanacaste, Cocos Island National Park, the Talamanca Range and La Amistad reserves shared with Panama, and the Precolumbian chiefdom settlements with the stone spheres of the Diquís. Arenal is not one of them, and neither are Monteverde or Cahuita. The mountain is a national park and a national symbol, which is a different and perfectly good thing.
Getting there
La Fortuna is roughly three to four hours from San José by road, longer in poor weather. The classic connection to Monteverde is the jeep-boat-jeep transfer across Lake Arenal, which takes about three hours and is far quicker and more pleasant than driving around the lake.
Visiting respectfully
The 1968 eruption killed people whose descendants live here. The villages that were destroyed are remembered locally, and the mountain is not only scenery to the people who live under it. Stay on marked trails, follow park staff instructions without argument, and do not treat a closure as an obstacle to work around.
Planning with LABUSA Travel
We build in the extra night that gives you a second chance at a clear morning, and we will tell you which hot springs suit the trip you are actually taking.
Sources
- Smithsonian Institution, Global Volcanism Program: the eruptive history of Arenal, including the end of the 1968 to 2010 eruptive period, drawing on reports from OVSICORI-UNA. Accessed 11 August 2026.
- SINAC, Sistema Nacional de Áreas de Conservación: the national protected-area system, which sets opening arrangements, capacity limits and access rules for every national park. Accessed 11 August 2026.
- Instituto Costarricense de Turismo: the national tourism board, including official entry guidance and protected-area visitor information. Accessed 11 August 2026.