In the lobby of Berlin's Radisson Blu Hotel is the world's largest cylindrical aquarium, the Aqua Dom. Its diameter is 11 meters, and the height of only the glass part is 16 meters. The total weight of the glass is about 150 tons. Inside the aquarium there is a transparent elevator that can accommodate forty people and takes tourists to the observation deck. The aquarium has about 2,000 fish of various species, swimming at different depths. Scuba divers are used to feed them and clean the aquarium.