The Green Line (Irish: Líne Uaine) is one of the two lines of Dublin's Luas light rail system.The Green Line was formerly entirely in the south side of Dublin city. It mostly follows the route of the old Harcourt Street railway line, which was reserved for possible re-use when it closed in 1958. The Green Line allows for passenger transfers at O’ Connell GPO and Marlborough to Luas Red Line services and also allows commuters to use Broombridge as an interchange station to reach outer suburbs such as Castleknock and Ongar.