World’s Largest Cylindrical Aquarium , AquaDom, Radisson Hotel Aquarium, Berlin; 25 meters high aquarium, with a capacity of 260,000 gallons of water and over 2,500 fish (56 species); visitors can travel through the aquarium using an encased elevator and get to the top where there is a restaurant and an open view of the city; hotel rooms can also experience the underwater view.