Intrigued? Just stare at this photo a bit and try to imagine what it might possibly be. I'm thinking... the secret lair of Jame Bond's nemesis? Better yet... evidence of a crashed spaceship!... (because it looks a lot like the top part of the U.S.S. Enterprise to me). But actually, it's a $239 million dome that covers the radiocative waste from nuclear explosion tests in the Bikini and Rongelap atolls. "The dome covers the 30-foot deep, 350-foot wide crater created by the May 5, 1958, Cactus test."