Arenal Volcano is the reason La Fortuna exists as a tourist destination. Its perfectly symmetrical cone rises 1,670 metres above the Alajuela plain and dominates every view in town. From 1968 until 2010 it was one of the most active volcanoes in the Americas, producing nightly lava flows visible from the road that drew visitors from around the world. Since 2010 it has been quiet.
The best way to experience the volcano is through the the national park, which has trails through the lava fields from the 1968 and 1992 flows. The park entrance is about 15 km from La Fortuna on the road toward Nuevo Arenal. Clear mornings give the best views of the cone — cloud typically builds around the summit by late morning. The summit itself is off-limits to hikers. At its base, the thermal springs and Tabacón resort are fed by geothermally heated water.
Arenal Volcano National Park protects the volcano and its surrounding lava fields and forest. The main trail system runs through the lava fields from the 1968 and 1992 eruptions, where you can watch the forest slowly reclaiming the rock — pioneer species working into cracks, ferns spreading across bare surfaces, birds perching in the few trees that found purchase. The walks are easy to moderate, with views of the volcano cone above.
The park has two main entrance points. The sector on the La Fortuna side has the most developed trail network. The El Silencio sector on the other side of the volcano is wilder and less visited. The hanging bridges section near the park entrance gives canopy-level views through the forest without the intensity of zip-lining. Entrance fees are modest by Costa Rican standards. The park is at its best in early morning when the volcano is most likely to be clear.