Hydropolis -- Dubai, United Arab Emirates
The opening of the much-delayed Hydropolis has been postponed indefinitely due to technical difficulties, but with an expected price tag of around $550 million dollars, the first proposed underwater hotel in the world may eventually prove to be the most expensive.
Depth: 65ft
Rate: N/A. Guessing it's a lot though, as the proposed property modestly claims it'll be 10-star.
Most exotic fish that'll stare disapprovingly at you through the glass: Hawksbill and Green turtles, both endangered, may pay you a visit.