The Radisson Blu Hotel, Berlin (Germany), which is situated on the River Spree, directly across from the Berlin Cathedral, appears from the exterior to be just another ordinary luxury hotel. Once you enter the hotel, nothing prepares you for the sight of the giant cylindrical Aquarium towering 25m (82 feet) smack in the center of the lobby.

Meet the Radisson Hotel’s AquaDom, the world’s largest cylindrical aquarium filled with one-million liters of saltwater and houses thousands of fish. With a 11 meter (36 feet) diameter, this monstrous tank has a glass-enclosed elevator through the center of the tank through which visitors and guest can travel up to reach the sightseeing point and restaurant under the glass roof.

The AquaDom is said to contain around 2600 fish from 56 different species and is maintained by the Sea Life Berlin Aquarium located next door to the hotel. Two full time Scuba divers are responsible for the care and feeding of the aquarium and its inhabitants, and one can often see them swimming around in full scuba gear with the fish as an added attraction. Sea Life Berlin conducts a Sea Life discovery tour which concludes with the two-story elevator ride through the middle of the AquaDom, during which guests learn about both the tropical-fish inhabitants and the architecture of the AquaDom.

Construction of the AquaDom was no easy feat, inaugurated in December 2003; the acrylic glass cylinder was manufactured in four pieces and constructed on-site on top of a nine meter concrete foundation. The pieces of acrylic were crane lifted into place during the construction of the hotel itself, as the rest of the hotel was gradually being built around the tank. The estimated cost of construction of the AquaDom is said to around 12.8 Million Euros.

Guest staying at the Radisson can opt for AquaDom facing suites which have windows looking directly to the Aquarium, which must be one amazing view to wake up to each morning.

Photos from flickr by: EagerEyes, nrubi, Jean-Louis Paquay, {erikv}, vxla