Each year 40 million people tread the white granite Main Hall of Union Station (1907), which is at once a train station, cultural centre (exhibition halls, nine cinemas), mall (130 shops) and food court. Washington's first shopping centre is also a fine example of the Beaux Arts style. Inspired by the Diocletian thermal baths in Rome, the barrel-vaulted ceilings are 30m high, and the façade borrows its design from the Arch of Constantine.