It was unique in containing below it a tunnel for a tramway, which started just north of Southampton Row, passed beneath Aldwych and continued to the Thames Embankment: this Kingsway tramway subway joined the North and South London tram systems. In 1958 the disused tunnel was reopened at the southern end to make a new connection, the Strand Underpass, for light traffic between Waterloo Bridge and Kingsway in order to reduce congestion. Also beneath Kingsway was a branch of the Piccadilly tube line from Holborn to Aldwych station on the Strand. It was closed in 1994. Aldwych station is still used for television and film sets that require underground scenes. During the Second World War the branch was used to store art treasures from the British Museum, including the Elgin Marbles.