Florida is a state located in the United States’ Southeast. Its boundaries are as follows: the Atlantic Ocean to the east, Georgia to the north, Alabama to the northwest, the Gulf of Mexico to the west, and the Straits of Florida and Cuba to the south. Florida is located on a peninsula between the Atlantic and Gulf of Mexico, making up about two thirds of the state. Without counting its numerous barrier islands, its coastline is the longest in the contiguous United States, measuring about 1,350 miles (2,170 km). It is the only state that shares boundaries with the Atlantic Ocean and the Gulf of Mexico. As of 2020, it ranked ninth in terms of population density and is the third most populous state in the union with a population of over 21 million.