Sunset Key Real Estate
Originally named Tank Island, Sunset Key was constructed by the U. S. Government, meant to be used as a fuel tank depot. They ran the fuel lines, but never filled the two tanks they finished (out of a planned twelve).
A developer bought it in 1986, and used the fuel lines as conduits for water, utilities and sewage. Power lines were laid along the fuel lines. It was sold and renamed Sunset Key in 1994. Now it is a private residence island, and you can only get there on a shuttle boat from the Margaritaville Marina.