Bok Tower Gardens is a National Historic Landmark. The 205-foot (62 m) Singing Tower was built upon one of the highest points of peninsular Florida, estimated to be 295 feet (90 m) above sea level,[4] and is listed on the National Register of Historic Places.By 1925, Bok had decided to replace the bird sanctuary's water tower with a stone water-and-bell tower.The Gothic Revival tower was built at the highest elevation of the site, south of a reflecting pool that reflects its full image. The tower is 51 feet (16 m) square at its base, changing at the height of 150 feet (46 m) to an octagon, with each of the eight sides 37 feet (11 m) wide.[3] It is built of pink Etowah marble and gray Creole marble, mined in Tate, Georgia, and coquina stone from St. Augustine, Florida.