As the world grows smaller and the luxury hotel scene expands, it's becoming more and more difficult to find a corner of this planet to call your own — not to mention find a hotel that doesn't look like a thousand others. That said, it's not impossible, as GAYOT's list of extreme hotels proves. In fact, we had a hard time choosing our favorites and even had to leave out some real treasures, including a drain pipe hotel on the Danube River and a vintage Boeing 727 in Costa Rica. But we think you'll agree that our selectivity has paid off. By vacationing at one of the hotels in our collection, you're sure to have an experience that takes you to the limit and beyond.