Sugarloaf Key Bat Tower
Built in 1929 to house bats that would eat the mosquitoes. The bats flew away the first night and never came back.
Richter Clyde Perky built a resort on Sugarloaf Key in the 1920s. The mosquitoes were destroying his business. He read about a man in Texas who had solved a similar problem by building towers to attract free-tailed bats, which eat mosquitoes by the thousands. Perky built the tower, imported the bats, and released them.
The Sugarloaf Key Bat Tower is at MM 17 on the Overseas Highway, visible from the road. It's on private property but can be photographed from the highway. The tower is listed on the National Register of Historic Places. Perky's resort never opened.
The bats left immediately and were never seen again. The mosquitoes remained. Perky's resort failed. The tower stood. It is now 95 years old, structurally sound, and completely empty. It is one of the most perfectly South Florida things that has ever happened.