Arenal Volcano

Declared in 1991, it protects the Arenal volcano, reckoned geologically very young, which lay dormant and forest-covered for centuries until on 29 July 1968 it erupted suddenly and violently, with almost no warning, burying three villages and killing more than 80 people. After that eruption the volcano kept up almost continuous activity for more than four decades, with lava flows visible at night that became one of the great tourist attractions of Costa Rica, until it entered a quiet period in 2010 which continues to this day.