Sunset Key is a private island accessible only by boat. It was developed by a company called Ocean Properties Limited who’s main business is luxury resorts. They bought the island in 1994. The original name of Sunset Key is “Tank Island” because it is a manmade island that came from all the fill dredged out of Key West Harbor to allow the Military Ships to come in. The Military put their fueling stations on the island. Therefore the name “Tank Island”. Many of the nautical charts still call it Tank Island and not Sunset Key.
Today Sunset Key is about 50/50 Guest Hotel Cottages ran by Opal Key Resort and Marina which is still owned by Ocean Properties Limited. The other half is very high-end luxury private homes. It would be safe to say they are all vacation homes. I only know of one family who lived there as their residence and after about 5 years they moved to a home on mainland Key West. The interior (Non-Waterfront) homes on Sunset Key will start at around $2,000,000. The waterfront homes will sell anywhere from $5,000,000 on the low end and up over $12,000,000 on the high end. The waterfront homes here very rarely come up for sale.