109 km west of Key West is the Florida Keys coral cay archipelago, covering approximately 1,700 coral islands and islets. This is a beautiful area where in 1935 the US government established a national park called the Dry Tortugas National Park. Dry Tortugas National Park is an archipelago of seven tiny coral islands surrounded by crystal clear waters of the Gulf of Mexico. Thanks to its location, the park is not visited often but it is a big attraction. It happened among other things thanks to the huge building called Fort Jefferson, which quickly became a major tourist attraction of the archipelago. Built in 1846 the fortress had become the headquarters of the American fleet, whose task was to control and containment of piracy in the Gulf of Mexico areas and the nearby Caribbean Sea. Construction of the fort, however, never was completed, and due to the high maintenance costs, mainly resulting from the devastation of frequent hurricanes in this area, in 1874 the army left the area completely.