LOS ANGELES, CA (Catholic Online) - Upon his discovery, de Leon named the islands "Las Tortugas, of "the turtles. "Dry" was later added to the islands' name as an attempt to warn mariners of the lack of freshwater in the area.

The Dry Tortugas became a fixture on Spanish ship maps. Seventy miles west of the Florida Keys, and in a prime location between the Gulf of Mexico and the Atlantic Ocean, the Dry Tortugas soon became a popular shipping corridor.

The Dry Tortugas also became notorious as the scene of hundreds of shipwrecks. The seasonal shallow waters and hazardous weather conditions led to the corridor's being dubbed "ship trap." To this day, a large collection of sunken treasures still lies beneath the surface waters. Seventeenth-century vessel remains, cannons, and glassware are among some of the maritime relics.

Fort Jefferson remains the area's crown jewel. Once Florida was acquisitioned from Spain in 1822, the United States began plans to erect a naval station that would help combat piracy in the Caribbean. Eventually, the U.S. Navy agreed on the Dry Tortugas as the site for their fortress, arguing that U.S. shipping in the Gulf Coast would be in jeopardy if a hostile power were to take over the islands.

In 1847, design plans were drawn up for a practically indestructible hexagonal fortress, complete with a massive 420 heavy-gun platform. Two sides of the fort measured 325 feet and four sides measured 477 feet. The structure stood 45-feet above sea level, surrounded entirely by a wall and a 70-foot wide moat. Though construction lasted for roughly thirty years, Fort Jefferson was never fully completed. Despite this, 16 million bricks were laid, making it one of the largest coastal forts ever built.

During the Civil War the fort was also used as a prison, mainly for Union deserters.

The fort was abandoned by the Army in 1874. In 1935, it was registered by President Roosevelt as a National Monument. The fort today operates as part of the Dry Tortugas National Park. Accessible only by boat or seaplane, the Dry Tortugas are considered to be one of America's most remote and least visited national parks.