"Head about 70 miles west to the remote beaches of Dry Tortugas National Park. The 100-square-mile park is reachable by boat or seaplane, and it's the least-visited national park in Florida, composed mostly of open seas and seven small islands. Garden Key is home to 19th century Fort Jefferson, its brick walls starkly contrasting the dazzling blue waters around it. You'll also find beautiful beaches on this island, and you can wade right into the water to snorkel above protected coral reefs. Basic campsites are available here on a first-come, first-serve basis, should you want to spend the night on the island." - Travel + Leisure Editors