External loan forbidden. Playa Grande on Costa Rica Pacific coast is one of the most important nesting beaches for the endangered Leatherback sea turtle (Dermochelys coriacea). Experts believe that land development, however, will destroy this unique nesting site. The Costa Rican Government and the local people are considering the leatherback turtles as an international treasure. It is their hope to make the Playa Grande and its surrounding area a national park in order to ensure the world and future generations the pleasure of these wonderful creatures.