Vieques is known as "La Isla Nena" (little girl island) and "Isabel Segunda" (Isabel II). Vieques was founded in 1843 by Francisco Saínz. It's 21 miles (34 km) long and 3 miles (5 km) wide, and it is 52 square miles (135 square km) in area. It was annexed to Puerto Rico in 1854. Vieques derives its name from the Taino Indian word for small island (bieques).

Beauty and history merge on this 21 by 4 mile island. Arawak Indians once lived here and it was an infamous heaven for pirates during the 17th century. Various European powers fought for control of Vieques. The Punta Mulas Lighthouse also known as Morropó was built in 1893. This old lighthouse still protects the port, boasts a reflector imported from Paris in 1895, which extends a beam that can be seen from as far as 16 miles.

Snorkeling is excellent, especially at Blue Beach. The island is also the home of phosphorescent Mosquito Bay. This rare and remarkable phenomenon is caused by millions of luminescent dinoflagellates lighthing up when disturbed by movement. The dinoflagellates, a tiny form of marine life, have characteristics of both plants and animals, their size range from about 5 to 2,000 micrometres (0.0002 to 0.08 inch).

There is an excellent historical museum at the beautifully restored fort, El Fortin Conde de Mirasol, located in Isabel Segunda. This fort holds the distinction of being the last fort constructed during the Spanish Empire in the New World, over time also served as a jail. After it's careful restoration in 1991 by the Institute of Puerto Rican Culture, the fort serves as the island's main museum, housing the Vieques Museum of Art and History and the Vieques Historic Archives. The museum contains the Vieques Historic Archives, which includes thousands of documents and other materials related to Vieques' history.