Location: Sark, England 
Purchased: $3.26 million*
Current Value: $6.02 million*

Described as a “windswept eyesore” by one publication, the billionaire Barclay brothers, Frederick and David, bought the eighty-ace Brecqhou Island in the 1990s for a few million. At the time of purchase, the island was a real fixer-upper.

The Barclays didn’t shirk from the challenge, and, with their considerable resources, they were able to turn the island into a nice getaway. Located in the English Channel’s Sark Island, the brothers built a mock-Gothic castle on Brecqhou. The castle has one-hundred-foot walls made of granite, two swimming pools, a helipad, and actual battlements. Brecqhou went from being an “eyesore” to something out of a fairy tale.