(54.539 ha). It`s situated on Osa peninsula, in Puntarenas province. Thera are about 500 species of trees throughout the park. This represents one-fourth of all the tree species that exist in Costa Rica (purpleheart, silk cotton tree - probably the tallest tree in the country).
Identification has been made of 140 species of mammals (tapir, giant antheater, puma, ocelot, jaguarundi, jaguar, tiger cat, margay, silky anteater, spider monkey), 367 of birds (harpy eagle), 117 amphibians and reptiles (poison dart frog, glass frog, olive ridley, green, letherback), and 40 offreshwater fish. It`s estimated that there are 6.000 species of insects. The park protects the largest population of scarlet macaws in the country.Zamieszkują go wszystkie gatunki kotów w Kostaryce. Wzbogaca go także największa populacja papug szkarłatnych w Ameryce Środkowej oraz największa populacja motyli i tapirów w Kostaryce. Ogólnie występuje w nim 140 gatunków ssaków, 367 gatunków ptaków, 187 gatunków płazów i gadów, 40 gatunków rzecznych żab i 6000 gatunków insektów.
In 1994 the park was closed for a few monthes due to the gold seekers. There is a conviction that, in Los Patos (hills in the eastern side of park) there are considerable gold-beds.
