the kingsway tramway subway is a cut-and-cover tunnel in central london. it was built for the london county council to join two tramway systems called the "north side" and "south side". used by single-deck tramcars only, but an upgrade between 1928 and 1931 meant that double deck trams could use it. the subway was closed in 1952. part of the subway is now the strand underpass, but the rest has not been changed very much and still has tram tracks inside it. it is now a grade ii listed structure.