This important national park has also an Emergency Zone Forest Reserve created on October 14 1972 for protecting the forest areas in the emergency zone of Arenal Volcano; this area is not open to the public. Its area is 230, 6 hectares.

Arenal is considered Costa Rica’s most active volcano and has been studied by seismologists for many years. Although the activity nowadays is less damaging you can still see ash columns, underground rumbling, glowing orange lava flows and sudden explosions on a daily base. With its perfect conical shape it allows breathtaking views of volcanic action in the summit. Almost every night the crater offers a spectacle of lights with its explosive eruptions.

The Arenal volcano is a 1,633 meters (5,300 feet) high mountain, which is perfectly conically shaped with a crater of 140 meters. The Arenal is geologically considered a young volcano and the age is estimated to be less than 3,000 years. For local residents it is also known as “Arenal Peak” , “Pan de Azúcar”, “The Canaste Volcano”, “The Costa Rica”, “Río Frío Volcano” or “The Guatusos Peak”.

The volcano was asleep for hundreds of years and exhibited a single crater at its summit, with minor fumaroles activity, covered by dense vegetation. In 1968 it had an eruption and destroyed the small town of Tabacón. Due to the eruption three more craters were created on the western flanks but only one of them still exists today.

The volcano is located in the northern zone of the country, fifteen kilometers southwest of La Fortuna in San Carlos. The temperature varies from 16 degrees Celsius (60,8 degrees Fahrenheit) in the high areas to 24 degrees Celsius (75,2 degrees Fahrenheit) in the low areas and the annually rainfall is around 5,000 mm (195 inches).

The Arenal Volcano area is an important watershed for the Arenal Lake Reservoir. Water from here is used for hydroelectric power, with the purpose of satisfying the electricity demand of the inter-connected national system and the Guanacaste irrigation projects.

This impressive volcano is surrounding by primary cloud forest and rainforest, its area is 13100 hectares, which abounds with flora and fauna species in multiple life zones, innumerable rivers, waterfalls and thermal hot springs.