34. Diego Garcia, Indian Ocean

Although it once belonged to the United Kingdom, Diego Garcia was used to settle a $14 million debt with the United States. The remote island was turned into a US Military base, and they are the only people allowed to enter. What looks like a tropical oasis is actually full of secrets. 

There are apparently 654 buildings on this tiny island, and 4,000 military personnel work there. Some people believe it is used as a secret military prison, but no one has gotten close enough to figure that out. People only know that this was the takeoff location for flights into Afghanistan and Iraq.