This famous national park has a terrestrial area of 46,515 hectares and a marine area of 78,000 hectares. The main headquarters for the joint administration of this park and of the Guanacaste National Park is located on the panAmerican Highway, 43 kilometers from the city of Liberia.

Santa Rosa is also an historic park. It was the scene of a military victory against Nicaraguan and American filibuster troops in 1856. To the right there is a photo of the old main house of the hacienda, now a museum. There are also a couple of rusting armoured personnel carriers left over from the last of military actions in Costa Rica.

The area of the park is of the dry Pacific. Much of the area is of savana with scattered patches of trees. The Guanacaste tree (Enterolobium cyclocarpum) is common here. This is the national tree. Some of the area is in thorn shrub where agaves and giant cacti grow.