Check It Out!I came across this article on Fogonazos about the worlds largest cylindrical aquarium.

The coolest thing about this is there is a glass elevator inside!! Check out their site for a ton of pictures!!

Here is some more information from Wikipedia:

The AquaDom in Berlin, Germany, is a 14 meter [45 feet] tall cylindrical acrylic glass fish tank with built-in transparent elevator. It is located in Berlin-Mitte, in the DomAquarée complex, which also contains a hotel, offices, a restaurant, and the aquarium Sea Life Center.

The AquaDom was opened in December 2003. It cost about 12.8 million euros [$16.5 million U.S.]. The acrylic glass cylinder was constructed by the U.S. company Reynolds Polymer Technology. The outside cylinder was manufactured on-site from four pieces; the inside cylinder for the elevator was delivered in one piece. The Aquadom is the largest acrylic glass cylinder in the world, with a diameter of over 11 meters [36 feet], built on a 9 meters [29 feet] tall concrete foundation. Filled with about 900,000 liters [237,754 gallons] of seawater, it contains some 2600 fish of 56 species. The feeding of the fish and the cleaning of the fish tank is performed daily by divers.