The most characteristic feature of this zone is the impressive and majestic Arenal Volcano, an almost perfect active cone 1,633 meters high, whose regular eruptions offer one of the most extraordinary and awe inspiring natural sights in Costa Rica.

There are four important types of vegetation in the zone, the perennial wet and very wet forests that cover about 47% of the area. There's also cloud forest and riverine woodlands, where several endemic species can be found, like the brunelia costaricensis and the epiphytic pineapple.