For anyone with the time and resources, Isla del Coco will make a memorable high point of a Costa Rica visit. This island receives only a fistful of visitors. Yet it is the nation’s prime dive spot, not to mention one of its most important seabird rookeries and a repository for endemic bird species.

Isla del Coco is a UNESCO World Heritage site. Traipsing the island is by permit only, although yachters call in, as do scuba divers operating form live-aboard dive vessels, which provide the only transport to the island. Encounters with harmless whale sharks and giant manta rays are also common. And inshore snorkelling amid the coral reefs reveals a world more beautiful that a casket of gems.