In 1994 the World Heritage Committee launched a world-wide search for areas that needed to be preserved due to their cultural or natural diversity of outstanding value. The area in Guanacaste that was chosen is in the northwestern part of Costa Rica, including Santa Rosa, Guanacaste, Rinc'n de la Vieja National Parks and the Junquillal Bay Wildlife Refuge.

These areas contain important natural habitats to support the diverse species, including one of the best dry forest habitats from Central America to northern Mexico. It is a vital habitat for endangered animal species including the Saltwater Crocodile, False Vampire Bat, Leatherback Sea Turtle, Jaguar, Jabiru Stork, Mangrove Hummingbird and threatened plants, including Mahogany, Guayacan Real and five species of rare cacti and bromeliads. The area also contains an estimated 230,000 species of terrestrial and freshwater organisms, which totals approximately 65 percent of the total species in Costa Rica. Scientists, worldwide, come to Guanacaste to research its unique properties and rare ecosystems.

The vegetation is extremely rare due to the high quantities of nickel and magnesium. The weather systems are also unique to this area, and have resulted in abnormally cold water that has created newly discovered coral reefs. Some of these reefs contained fossils that were 80 to 100 million years old.

Cocos Island National Park is also included in the World Heritage Site designation because it provides a vital habitat for marine wildlife. The park is a famous dive site for viewing large marine species such as sharks, rays, tuna and dolphins. It also remains the only island in the tropical eastern pacific with a tropical rainforest.

Preserving this area has resulted in a balancing act between the Ministry of Environment and the tourism and fishery trades. They have finally completed an agreement that allows dive boats and local fishermen limited access to the area. This privilege is accompanied with a strict set of rules and may be discontinued at any time.

Costa Rica is unique in that the government and the people have a sincere interest in preserving the environment. One of Costa Rica's ex-presidents was quoted as saying, "Once we grew up with our backs to the ocean, now we are doing something about that".