The Arenal volcano represents the perfect image which one has of a volcano in eruption. Initially because this mountain is well insulated and dissociates neighbouring mountains by its elegance and its triangular form. (With its 1 633 m of altitude, the Arenal volcano are easily locatable, of all directions, and particularly on the western side, where the lake Arenal is.) Then because this mountain is regarded as one of the most active volcanos in the world.

Nacional Arenal ( 6$ Parks; tlj 8h with 22h; 460-1412 or 695-5908, 460-0644), of a surface of 12 016 ha and created September 1994, formed part of Area de Conservación Arenal. This very young park aims protecting this area, but also at informing the visitors about this extremely active volcano. The place more visited park is the Watchtower, located at 1,3 km of the entry. It is possible to reach foot it, via a small path, or conveys some (parking). This point of view, based with the foot of the volcano, constitutes an excellent place to admire, listen to and feel all its powerful activity. One easily distinguishes the many lava flows which cut through a path until the base of the mountain by consuming all on their passage. Perhaps according to the day, you will see flights of dust and ashes to spout out top. Moreover, it is not rare to feel a terrestrial jolt accompanied by grondements very perceptible, as if the Arenal volcano wanted not to leave any doubt about its power and its appalling destroying capacity.