St. Augustine, Florida, founded in 1565, is the oldest continuously occupied city and port in the continental United States and it is also home to the first lighthouse established in Florida. When the United States gained possession of Florida in 1821 one of the first items of business was to establish a beacon in the oldest port. The Spanish authorities had maintained a watch tower on the north end of Anastasia Island since the 16th century. When the US decided to build a lighthouse they first surveyed the old coquina tower to see if it could be adapted for use as a lighthouse.