The Braulio Carillo National Park is the largest park in Costa Rica , with an extension of 50,000 Hectars. It is located in the middle of the country , straddling the mountain range between the Poas and Irazu volcanoes . Volcanoes found within the park are Barva and Cacho Negro. The highest point of the park is the Barva lake , located at roughly 10,000 feet altitude and which formed as the result of water accumulating in the crater of the Barva Volcano.