This park is found in Guanacaste, 22 Km NE of the city of Nicoya. It was founded in 1974 and has an area of 2,295 hectares. It has a major limestone hill, Barra Honda Hill, and is well known for its caves.

The main feature of the park is its system of independent limestone caves, 19 of which have been explored up until now. The most attractive and interesting are: La Trampa (The Trap), El Terciopelo (The Ferdelance) and La Santa Ana (The Saint Ann).

La Trampa is the deepest. From the entrance down to the first chamber, there is a vertical drop of 52 meters. This cave has the largest chambers yet discovvered in this park. One is of pure white calcite and is very beautiful

The terciopelo has the greatest number of formations. One famous one is called the "Organ" and, when lightly struck in different places, it delivers different tones of sound.

Another cavern is called El Pozo Hediondo (The Stink Hole) and contains large numbers of bats. The masses of guano that result give the bad smell that named the cave.

In the Nicoya Cavern were found many Precolumbian artifacts and human remains.