This 300-hectare island rises 30 meters above the ocean's surface and is clearly visible from the western end of the Osa Peninsula, located some 15 kilometers away. The distance was not an obstacle to the pre-Columbian peoples that inhabited the mainland and utilized the island as a burial site. Not only did they ferry their dead across this stretch of open water, but they also transported large spherical stones to the cemetery on top of the island. Some of these can still be seen today together with fragments of pottery and stoneware left behind by careless tomb robbers during the latter half of the 20th century.

The diversity of plant and animal species on Caño Island pales in comparison to that of Corcovado National Park on the nearby mainland. For example, fewer than 60 species of trees and only four species of orchids are known to grow on the island. Likewise, there are just four species each of snakes, lizards, and frogs on the island, and only a dozen kinds of birds breed on this offshore sanctuary. This paucity of terrestrial flora and fauna results from the isolating effects of being an island.

However, where Caño really comes into its own in terms of diversity is in its marine realm. The oceanic sector of the reserve protects 5,800 hectares of marine habitat surrounding the island. A mask, snorkel and fins are all you need to appreciate the abundance and variety of aquatic life just below the surface. The beach in front of the ranger station is a good swimming beach and the submerged rocks on either side provide hours of snorkeling entertainment with such colorful fish as Moorish idols, blue parrotfish, king angelfish, spotted sharpnose puffers, barberfish and rainbow wrasses. Scuba diving is also permitted for those who are certified.

Along the little stream that flows beside the ranger station you might get a good look at the so-called Jesus Christ lizard. More properly termed lineated basilisk lizards, these brownish reptiles can't actually walk across water, but they do run across the surface, reared up on their hind legs so that the flaps of skin on their long toes spread out and function as miniature paddles. The little ones are best at executing this startling maneuver, but if you find a fully developed adult male with its head crest and dorsal fins, you will be looking at an awe-inspiring creature.

Getting there: Access is by boat only. Most visitors to the island come from the lodges in the Drake's Bay area. (The lodge or your travel agency can make arrangements for you to fly to the Palmar airport on a regularly scheduled commercial flight, be driven to the town of Sierpe, and then taken by boat through a large mangrove system and out the mouth of the Sierpe River into the ocean and across to Drake's Bay.)

Fishing: Several of the lodges in the Drake's Bay area offer the option of deep-sea fishing. The waters around the island are particularly well-known for their abundance of Wahoo, Roosterfish, and Pacific Cubera Snapper, but billfish and tuna are also out there.

Climate: Caño Island receives even more precipitation than the adjacent mainland, and so is hot and very humid all year long. From February through April is the driest part of the year.

History: There is much conjecture about the use of the island in pre-Columbian times. Some researchers suggest that the island was actually inhabited at some point. Most assume it was used only as a final resting place, and many assert that this form of interment was reserved only for the more privileged members of the native societies. Sadly, due to the ransacking of the burial sites prior to any investigations by archeologists, we will probably never know with final certainty the exact role that the island played in these vanished cultures.

Caño Island was first given protection as part of Corcovado National Park in 1976. The declaration came in response to a well-organized outcry by the Costa Rican Association of Biologists which in 1973 protested energetically against the leasing of the island to a foreign company with plans to develop it for international tourism. The result was a victory for local conservationists, and one in which scientific arguments outweighed economic interests in the final decision.

Eventually the National Park Service gave the island its own administration by separating it from Corcovado and making it a biological reserve.