Dry Tortugas National Park - Florida

Established October 26, 1992

64,701 acres

In the Gulf of Mexico, about 70 miles west of Key West, Florida, a 7-mile-long archipelago of seven low-lying islands forms the centerpiece of Dry Tortugas National Park, a bird and marine life sanctuary with some of the healthiest coral reefs remaining off North American shores. Towering incongruously in the midst of this subtropical Eden is Fort Jefferson, a relic of 19th-century military strategy. The largest American coastal fort built in that century, it sprawls over 16-acre Garden Key

Barely 85 acres of the park's 100 square miles are above water. Three easterly keys are little more than spits of white coral sand. A stone's throw from park headquarters in Fort Jefferson, Bush Key is home to a tangle of bay cedar, seagrape, mangrove, sea oats, and prickly-pear cactus that reflect the original "desert island" character of the islands. The chain ends about 3 miles west with 30-acre Loggerhead Key, where a lighthouse completed in 1858 still flashes a beacon to mariners.

Spanish explorer Juan Ponce de Leon, the first European to describe the Florida peninsula, dropped anchor here in 1513, found pellucid waters teeming with green, hawksbill, leatherback, and loggerhead turtles, and so named the islands las tortugas. For the next three centuries, pirates relied on the turtles for meat and eggs; they also raided the sandy nests of roosting sooty and noddy terns, over 100,000 of which descend on Bush Key every year between March and September. By 1825, when the islands' first lighthouse began to alert sailors of surrounding reefs and shoals—a grave for more than 200 ships wrecked here since the 1600s— nautical charts warned that the Tortu-gas were "dry."

In 1846, US Army strategists were concerned that hostile nations could disrupt shipping lanes in the Gulf of Mexico. As a result, they decided to build a 450-gun, 2,000-man fort on Garden Key. The intimidating bulk of the 50-foot-high, three-level hexagon, whose 2,000 arches run half a mile around, spared it from ever having to fire a shot in anger. A Union prison for Civil War deserters, it also held physician Samuel Mudd, who was convicted of conspiracy in Abraham Lincoln's murder after he (unknowingly, he claimed) set the broken leg of fugitive assassin John Wilkes Booth. He served four years before being released.

Unfinished after nearly 30 years of intermittent construction, the "Gibraltar of the Gulf" succumbed in 1874 to several factors: yellow fever, hurricane damage, and the new rifled cannon, which rendered its 8-foot-thick walls obsolete. Revived in 1898 as a Navy coaling station—the battleship Maine steamed from here to its infamous destiny in Havana Harbor 90 miles south—the fort was permanently abandoned in 1907.