Alejandro Selkirk is one of a trio of islands that comprise the Juan Fernandez Archipelago, a UNESCO World Biosphere Reserve that lies about 375 miles off the coast of Valparaiso. The island is named for Alexander Selkirk, the real-life inspiration for Robinson Crusoe, who was marooned on the island in the early 1700s. (Another island in the chain is named for the iconic Daniel Defoe character; the third is Santa Clara.) A biogeographic barrier caused by the Humboldt Current passes between continental Chile and the Juan Fernandez Archipelago, creating a distinct ecosystem that more closely resembles those found in the South Pacific than South America. The islands are home to numerous rare and endemic flora and fauna, including the Juan Fernández fur seal, the critically endangered firecrown hummingbird, and three species of petrel: the Juan Fernández, Stejneger’s, and Masatierra. They also are a mecca for diving enthusiasts, renowned for their clear waters and diversity of sea life. Alejandro Selkirk Island is mountainous and densely wooded; cliffs along its rugged eastern coast reach upward of 3,280 feet high. The critically endangered Masafuera Rayadito is a rare bird species endemic to the island, as is the Juan Fernández orchid and other species.