He's a hotel fish tank that may be more spectacular than the hotel itself. The AquaDom, in Berlin's Radisson SAS Hotel, is 52 feet deep, 36 feet in diameter, and holds some 2,500 tropical fish. And just to make the tank completely unique, the hotel's glass elevator runs right through the middle of it!
The AquaDom was created by International Concept Management, and it is the largest cylindrical aquarium in the world, constructed from 150 tons of acrylic bonded together to look seamless. The tank holds more than a quarter of a million gallons of artificial seawater, and is so deep that a diver visiting the bottom of the tank must take precautions to avoid getting decompression sickness.