For most of us, buying a private island is just a fantasy. But it's still fun to find out who does own them, and how much they paid! See what you know about private islands in our Ultimate Fantasy Island quiz.
Athina Onassis, who inherited Skorpios from her grandfather Aristotle, was widely rumored to have sold the island to Georgio Armani in 2009, but both sides denied the transaction, leaving Athina its sole owner.
This pristine getaway in the Out Islands of the Bahamas features several small cottages, all solar-powered.
The first park of its kind in or around the Caribbean, the Exuma Cays Land & Sea Park is an example of a "no-take" marine fishery reserve, allowing populations of both endangered and commercially important species to thrive there.
Great Hans Lollik and Little Hans Lollik are surrounded by the crystal clear Caribbean, less than 2 miles off the northern shore of St. Thomas, in the U.S. Virgin Islands.
The owner of this 11-acre private island on Lake Mahopac waited for the lake to freeze, then drove supplies out on John Deere tractors. Try that in the tropics!
Frank Lloyd Wright drew plans for Petra Island in 1950, but the home was not completed until nearly 50 years after his death, leading purists to insist that the house is merely inspired by Wright, and not a true Wright creation.
When he first sighted High Cay, a 31-acre island in what we now call the Bahamas, Columbus believed he had finally reached India. This piece of world history can now be yours for the asking price of $3 million.
Today, the luxurious 74-acre getaway has an estimated value of somewhere around $60 million, but Branson paid just $100,000 for the then-undeveloped island in 1978.
When you stay in the seven-room hacienda on Isla de sa Ferradura, an attentive staff will serve you made-to-order food and drink almost anywhere on the 14-acre island, but you'll have to pay extra for caviar and certain specialty wines.
Marlon Brando bought this ring of 13 idyllic islands in 1965 and stayed there frequently until his health began to deteriorate in 1990.
Marlon Brando fell in love with the islands while filming "Mutiny on the Bounty" in and around Tahiti.
The island is full of vegetation, and covered in lush forests of olive and fruit trees.
Balboa's travels took him within shouting distance of Isla Majagual and Isla Maje, which are in the Gulf of Panama, just a few miles from the Pacific coast.
Tom Hanks (and his film pal Wilson) toiled away on the island of Monuriki, Fiji during the making of the movie.
It's standard for brokers to add a mark up of 20 percent or more to the top of an island's sale price. This commission goes straight to the broker, and sometimes the seller isn't even aware of it.
The island can accommodate up to 25 total residents, so ask 24 of your best friends to help you cover the bill for one of the most expensive island rentals in the world.
Water, water everywhere -- make sure some of it is fit to drink!
Marlon Brando advised Depp to think about things like the island's water supply, as well as its elevation above sea level in case of hurricanes and tropical storms.
These massive feats of engineering and excess are found in the Persian Gulf, just off the city of Dubai, United Arab Emirates.
Gibson reportedly spent $9 million in 2005 to buy the 5,400-acre Mago Island, one of the largest privately owned islands in the South Pacific.