The Humboldt Box glows against the Berlin city skyline during a test illumination on Monday evening. The architectural oddity, which officially opened to the public on June 30, is actually an advertisement for another project: a partial rebuilding of the Berlin City Palace, where Kaiser Wilhelm II once lived. The royal palace suffered extensive damages in World War II and was later torn down completely. Plans to rebuild it have been in debate for years.

One level of the Humboldt Box is dedicated to a miniature plan of the palace and information about its rebuilding. The other two levels will house diverse exhibits on everything from Chinese porcelain to ecological consequences of the African frog trade. In Germany, opinion on the Humboldt Box is divided, with some hailing the structure as an exciting step forward in the rebuilding of the Berlin City Palace, and others deriding it as little more than an architectural vanity project for the German capital.