Built on a rocky island in the Drina River, near the town of Bajina Basta, Serbia, this wooden house was cobbled together by a group of boys in 1968 as a clubhouse for sunbathing and recreation. The house, which comprises one room and a covered porch, is now owned by the Bajina Basta Kayak Club.
Marble House in Newport, Rhode Island - An $11 million birthday present for Alva Vanderbilt from her husband, William, this Gilded Age mansion was built between 1888 and 1892. Designed by Richard Morris Hunt, this Beaux-Arts masterpiece served as the Vanderbilt's summer cottage. The 50-room home influenced the transformation of Newport into the upscale resort town it is today.