The building was built in the 1880s and was used as a gallery. Its built in an unique style called hanoverian functionalism - a lot of cast iron and influences of romanesque, gothic, baroque and constructino engineering. Today only the stairways remained, due to WW II. The building is located in the innercourtyard of the state theater.
As the stairways are not regularly open you should visit a theatrical performance or a party of "Calamari Moon" at the weekend. They play soul, jazz, funk and electro and invite international djs: http://www.calamarimoon.de For the theater check the state theater: http://www.staatstheater-hannover.de