GUM is the name of the main department store in many cities of the former Soviet Union, known as State Department Store during the Soviet times. Similarly-named stores were found in some Soviet republics and post-Soviet states. The most famous GUM is the large store in the Kitai-gorod part of Moscow facing Red Square. It is currently a shopping mall. Before the 1920s, the location was known as the Upper Trading Rows. Nearby, facing The Bolshoi Theatre is a building very similar to GUM, known formerly as the Middle Trading Rows, now the TsUM, about the same size as a large North American shopping mall, with a glass roof.