Corcovado National Park is a National Park on the Osa Peninsula, in Osa Canton, located on the southwestern regions of Costa Rica, which is a part of the Osa Conservation Area. Corcovado National Park was established on October 24, 1975 and occupies an area of 424 square kilometres. It is currently the largest park in Costa Rica and extends over about a thir…Corcovado National Park is a National Park on the Osa Peninsula, in Osa Canton, located on the southwestern regions of Costa Rica, which is a part of the Osa Conservation Area. Corcovado National Park was established on October 24, 1975 and occupies an area of 424 square kilometres. It is currently the largest park in Costa Rica and extends over about a third of the Osa Peninsula.