Santa Rosa is one of the country's most historically significant parks. The ranch house "La Casona" and the stone corrals built in colonial times were the site of one of the most famous battles in the history of Costa Rica: the Battle of Santa Rosa, fought  against American invader William Walker and his mercenary army on March 20, 1856.
The old ranch has been restored to give a glimpse of rural life in the 19th century , and contains a small ecological museum.

The park recently increased it's ecological assets, with the addition of Guanacaste National Park next door. Santa Rosa comprises large stretches of rare tropical dry forest, extensive mangrove estuaries and several spectacular beaches.

There are plenty of trails along the main road, but access to Nosara Beach is limited to hikers and four-wheel drive vehicles. Santa Rosa stretches from the Inter-American Highway to the coast while Guanacaste National Park stretches east from the highway up around Orosi Volcano, and at the moment has fewer trails and limited access. Between the two of them, these parks contain the largest protected area of tropical dry forest left in the Americas, which is home for cougars, jaguars, tapirs, crocodiles, eagles, coyotes, anteaters, 260 species of birds and countless insect species. The parks are also the focus of an ambitious ecological restoration project.

The beaches at Nancite and Naranjo are of great scenic beauty and have become important nesting sites for two species of sea turtles; The olive ridley leatherback and Pacific green. The largest arrivals of olive ridley turtles in all of tropical America take place at Nancite Beach.

Because of the park's enormous biological wealth and variety together with the ease with which one can reach it, Santa Rosa has become an important international research center for studying the ecology of tropical dry forest.

Santa Rosa Park, together with the territory that extends to the east between the Pan-American Highway and the Atlantic side of the Guanacaste Mountain Range, is the region where the project to create the Guanacaste National Park is taking shape. The purpose of this park is to establish a wilderness area of 85,000 Ha. which will be large enough to guarantee the continuing existence of the populations of plants and animals and the original, tropical dry forest habitats of the region.

La Casona de Santa Rosa