Carbuncle Passage follows the line of the Moselle river.
The Moselle stream, whose names derives from ‘Mosse-Hill’ (Muswell Hill), the location of one of the stream’s sources, ran its meandering course north-eastwards from Hornsey, bending due south at the present junction of the High Road and White Hart Lane and continuing along the west side of the High Road to Scotland Green. Here it turned eastwards as Garbell Ditch, later known as Carbuncle Ditch whose course is commemorated by Carbuncle Passage, with a further ditch forking south-eastwards to the Hale.
The stream was incrementally culverted in the 18th and 19th centuries, and by 1864 only short sections remained open along the High Road.