Culebra original names were "Isla Pasaje" and "Isla de San Idelfonso" in honor of Bishop San Idelfonso de la Culebra. Cayetano Escudero was the first Delegate of Culebra appointed by a Governmental order from Vieques on August 2, 1881.

Located 27 km (17 miles) east of Puerto Rico and 19 km (12 miles) west to Saint Thomas, its dimensions are about 11 km (7 miles) long and 5 km (3.5 miles) wide. Its total area including surrounding Cays is 7,000 acres.

The capital is Dewey, which contains most of the archipelagoes 2000 souls. The municipality of Culebra includes all surrounding islets: Cayo Norte, Cayo Ballena, Cayos Geniqui, Culebrita, Arrecife Culebrita, Cayo de Luis Peña (named after its second owner), Las Hermanas, El Mono, Cayo Lobo, Cayo Lobito, Cayo Botijuela, Alcarraza, Los Gemelos, and Piedra Steven.

On June 26, 1903, President Theodore Roosevelt established the Culebra Naval Reservation. With the outbreak of WWII in 1939, the Culebra Archipelago became the primary gunnery and bombing practice site for the U.S. Navy and continued to be used for these purposes until 1975.

On February 27, 1909, a bird refuge was established, making it one of the oldest refuges in the system. Since then much of the island and the surrounding 23 islets including Culebrita are protected by the U.S. Fish and Wildlife Service as a nature preserve, making the islands one of only two nesting sites for giant sea turtles in the U.S. The Culebra National Wildlife Refuge, 600 ha, protects large colonies of sea birds (with approx. 85 species), particularly terns, red-billed tropic birds and boobies, and nesting sea turtles. The refuge is accessible by ferry from the east coast or by plane from San Juan.

Culebrita is the largest cay near Culebra. Culebrita's beach is the finest of white sand and the water visibility is almost unlimited. It is accessible only by boat, and boasts the oldest operating lighthouse in the Caribbean. The Culebrita Lighthouse was built in 1886. In 1975, the Navy and Coast Guard closed the facility. Since then, the lighthouse has sustained heavy damage from hurricanes and vandalism. In 1981, the old lighthouse was registered on the National Register of Historical Monuments of the United States.

Luis Peña is the second largest cay near to Culebra. Many sandy beaches can be found on this cay, as well as wonderful coral reef located on the SW side, perfect for snorkeling.