Created in 1973, this rather large national park, 14,083.9 hectares, is centered around the old, but still quite active, Rincon de la Vieja Volcano. This mountain reaches 1,916 meters above sea level and has nine eruptive points, one the active crater and the others, extinct older craters. Just to the South of the main crater there is a beautiful, clear water lake. The volcano has a number of active fumerols and every few years lanches great clouds of gas and ash.

At the foot of the volcano there is are two areas, Las Pailas(low pans for cooking or boiling things) and Las Hornillas (little ovens) respectively. These areas have springs that produce streams of very hot water and others that produce boiling, sulfurous mud. The are a number of little mud "volcanos".

The park has many varied habitants. These change with elevation, land inclination and the effects of eruptions. The lower reaches of the volcano has dense forest. Above 1,400 meters one sees dense, low, tangled shrub-like forest, sometimes reffered to as "elfin forest". The top of the cone is mainly ash and scoria with little vegetation, although the "poor man's umbrella" (Gunnera insignis) is common there.

In some areas copey trees (Clusia major) form almost pure stands and there some felines, tapirs and wild turkey are fairly numerous.