The Florida Keys are a coral cay archipelago located off the southern coast of Florida, forming the southernmost portion of the continental United States. They begin at the southeastern coast of the Florida peninsula, about 15 miles (24 km) south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry Tortugas. The islands lie along the Florida Straits, dividing the Atlantic Ocean to the east from the Gulf of Mexico to the northwest, and defining one edge of Florida Bay. At the nearest point, the southern part of Key West is just 90 miles (140 km) from Cuba.