Corcovado National Park (Spanish: Parque Nacional Corcovado) is a National Park on the Osa Peninsula in the South West of Costa Rica (9° North, 83° West), which is part of the Osa Conservation Area. It was established on 24 October 1975, and encompasses an area of 425 km² (263 mi²). It is widely considered the crown jewel in the extensive system of national parks and biological reserves spread across the country. The ecological variety is quite stunning. National Geographic has called it "the most biologically intense place on Earth". Not only is the park very popular with tropical ecologists, a visitor can expect to see an abundance of wildlife.
The park conserves the largest primary forest on the American Pacific coastline and one of the few remaining sizeable areas of lowland tropical rainforests in the world. Logging usually takes place in lowland areas because those areas are more accessible and contain the largest and most economically valuable trees. But those habitats are also usually the richest in biodiversity. So even though still approximately half the tropical rainforests on Earth remain, what is left of the originally rich lowland tropical rainforests is usually too small to support the original natural biodiversity. Larger animals, especially, need a large habitat free of human activity. Unfortunately this means that even tourism, the economic incentive for Costa Rica and other developing nations to preserve and protect parks such as Corcovado, actually threatens the long-term biodiversity of the park. 
Corcovado is home to a sizable population of the endangered Baird's Tapir and even a small population of the very rare Harpy Eagle. The park's rivers and lagoons are home to large populations of both the American crocodile and Spectacled Caiman, along with Bull sharks. Corcovado is also one of the final strongholds ofthe Jaguar within Central America and several other felines are also present, including Ocelot, Margay, Jaguarundi, and Puma. All four Costa Rican monkey species can be seen within the park, including the endangered Central American Squirrel Monkey, White-faced Capuchin, Mantled Howler, and Geoffroy's Spider Monkey. Other mammals present include Two-toed and Three-toed Sloth, Northern Tamandua and Silky Anteater. Poison dart frogs and several species of snake (including the venomous Fer-de-Lance and Bushmaster) are also common within the park.
The abundance in wildlife can in part be explained by the variety of vegetation types, at least 13, including montane forest (more than half the park), cloud forest, jolillo forest (palm swamp), prairie forest, alluvial plains forest, swamp forest, freshwater herbaceous swamp and mangrove, together holding over 500 tree species, including purple heart (tree), poponjoche, nargusta, banak (tree), cow tree, espave and crabwood (tree). Another reason for the diversity (as with all of Costa Rica) is that it lies on a north-south corridor for flora and fauna; part of the "land bridge" and wildlife corridor that links the large continents of North America and South America.
As when visiting any sensitive natural area, please be sure to clean all of your hiking and/or camping gear (in particular shoe/boot soles and tents) prior to visiting to decrease the chance introducing non-native seeds.
Corcovado National Park is open to the public and can be visited on day trips and for overnight visits. As of January 2009, admission is $10 per person per day for non-Costa Rican residents.
Reservations for overnight visits in the park can be made in Puerto Jiménez on the east coast of the peninsula. One may camp or stay indoors at one of several ranger stations equipped with bunks. If one wants basic meals served, reservations should be made about a week in advance. Take note that researchers get preference over other visitors (though there is usually enough room for self-catering campers).
One can make day visits into the park from several lodging options on both the north and south entrances to the park, as well as through organised excursions that fly into the park.
Corcovado National Park is open to the public and can be visited on day trips and for overnight visits. As of January 2009, admission is $10 per person per day for non-Costa Rican residents.
Reservations for overnight visits in the park can be made in Puerto Jiménez on the east coast of the peninsula. One may camp or stay indoors at one of several ranger stations equipped with bunks. If one wants basic meals served, reservations should be made about a week in advance. Take note that researchers get preference over other visitors (though there is usually enough room for self-catering campers).
One can make day visits into the park from several lodging options on both the north and south entrances to the park, as well as through organised excursions that fly into the park.
One can get to the Corcovado National Park via Puerto Jimenez or Drake Bay. These two towns serve as the main entry points to the park. There are two tracks, one coastal and one inland, and four ranger stations in the park where one can stay overnight; three at the park entrances and one at the intersection of the two tracks. One track runs Northwest to Southeast along the coast to Estacion La Leona, with the Estación Sirena roughly in the middle. The second track runs inland from Estacion Sirena to Estación Los Patos at the Eastern end of the park. One can fly into the park (via chartered aircraft) to Estación Sirena, from where one can follow relatively short loop-trails. Carate (near Estacion La Leona), also has an airstrip and road access from Puerto Jimenez. To walk through the park one needs a reasonable fitness, at least two or three days, good planning and caution. During the wet months (July to November) parts of the park may be closed.
More detail on visiting Corcovado at wikipedia
