The AquaDom in Berlin, Germany is an eight-story-high aquarium, housed in the Radisson Blu.
It was opened in 2004. It has a diameter of about 11 m (36 ft). It weighs more than 2,000 tons when filled to the top (with 260,000 gallons of water), and it holds approximately 1,500 fish.
It’s located in the middle of a hotel with shops, restaurants, and the Berlin Sea Life Center.
Visitors can ride a glass elevator inside a tube that runs directly through the middle of the tank.
Treat yourself: https://www.visitsealife.com/en/berlin/