This 32,512 hectare national park was founded in 1991 in the Province of Guanacaste, some 36 kilometers North of the city of Liberia. The park centers around the Orosi and Cacao Volcanos. It should be noted that the headwaters of the great Tempisque River lies within the park between Cacao Volcano and Orosillito Mountain.

Since the park covers both the wet Caribbean side as well as the drier Pacific side, it contains a wide diversity of climatic zones. The primary forest on the tops of Cacao and Orosi Volcanos contains a wide variety of epiphytes, especially bromeliads and orchids. Because of the wide climatic variations, there are also wide variations in the numbers of species of plants and animals. The are over 300 types of birds and an estimated over 5,000 species of moths and butterflies.