Arenal Volcano (1,633 meters), or Volcán Arenal in Spanish, is Costa Rica’s most active volcano- and one of the most active on earth- and a must see on any visitors itinerary. However, it is often covered in clouds and getting to see an eruption is a matter of luck. The dawn and early morning hours are usually best, before the clouds roll in; seasonally, you stand a reasonable chance in dry season, and a better chance in rainy season.
Arenal's eruptions are frequent but moderate- and can be viewed without danger- currently best from from the roadside passt the entrance to the Park.
On 29 July 1968, it erupted. A massive explosion wiped out the villages
of Tabacón -site of Tabacon Hot Springs now- and Pueblo Nuevo, whose
entire populations perished. The last major eruption of Arenal occurred on August 23, 2000. The volcano heats several hot springs nearby, including Tabacon, a popular tourist destination.