The Caño Island National Park is an amazing marine biological reserve in Costa Rica. This island is just northeast of the Corcovado National Park Coast. A former burial ground dating back to the pre-Columbian era. In addition to the evergreen forest of this island, there is yet more beauty underwater. A good water visibility (rare for Costa Rica), spectacular variety of stunning marine flora and fauna and even gorgeous coral reefs. This is one of the good underwater adventure diving spots in the world. You might see: sea turtles, dolphins, stingrays, manta rays, moray eels, barracudas, tuna snapper and grouper. You may see them swimming alongside a variety of sharks and humpback or pilot whales.