how about this for a tank.
its in the radisson hotel in berlin and has an elevator through it
here what it says about it
AQUADOM
Standing majestically in the lobby of the Radisson SAS Hotel Berlin, the world's largest cylindrical aquarium, the AquaDom. Filled with one million litres of saltwater, and home to about 2,500 tropical fish, the AquaDom can be seen from several of our guest rooms. Guests can dive into this amazing world in a two storied glass elevator and learn more about the fish housed in the unique AquaDom and its architecture.
heres a link
http://www.berlin.radissonsas.com/rsas_link/en/berza/rsasHotelArticle/1058339121937.html