Roughly shaped like a lima bean, Mona Island (Isla Mona)is situated in the center of the Mona Passage (50mi/81km west of mainland). Although the island is actually closer to the Dominican Republic, it has always been associated with Puerto Rico since being discovered by Columbus in 1493. Mona Island has been a nature reserve since 1919 and uninhabited for more than 50 years. The area of the island is 13,000ac/5,263ha, with a semi-arid/sub-tropical climate.
There are many high cliffs, coral reefs, mangrove forests, caves, beaches and unusual, rare wildlife. All of these elements make Isla Mona a good choice for those interested in hiking, diving, kayaking, and other water activities. The Mona Iguana, which reaches 4ft in length, is found nowhere else in the world. There is evidence of Taíno Indian settlements on the island, including petroglyphs, relics and pictographs. The first lighthouse to be built by the U.S. in Puerto Rico (1900) also sits on the island and is registered with the National Trust.