In south London, the area between the South Western main line from Waterloo through Wimbledon and the London, Brighton & South Coast main line from London Bridge to Croydon and eventually Brighton remained unexploited until the early 1860s. It was then crossed in a roughly north west to south east direction by the London, Chatham & Dover, and the West End & Crystal Palace, later London, Brighton. There was however no line running across these lines in a north east to south west direction from London Bridge. Both the Chatham and Brighton companies were interested in this area and eventually they agreed on a proposal that the Brighton company build a line from Peckham to Sutton.

This was dependent on the agreement of the Governors of Dulwich College which owned the land. This was eventually obtained, but at a price which included provision for boys attending the school to travel at half the normal fare. Another condition was that a station be built on Red Post Hill at which all trains except express trains were to stop, and where only passengers and no goods could be handled. Furthermore, all bridges were to be designed by the Architect to the Governors.

The result is the attractive station at North Dulwich, built over a cutting. It is a brick building with stone dressings and a three arched loggia across the asymmetrical front, and a two storey tower with large windows. Covered stairways lead to the platforms with their old wooden awnings.

A short distance to the south the railway crosses a 34 arch brick viaduct with pierced stone parapet and spandrels decorated alternately A.C. (Alleyn's College) and the year (1866). At the crossing of Burbage Road the viaduct is interrupted by a bridge with five sided brick abutments and supported by six cast iron columns located three to each side of the road. At the crossing of the Chatham line from Victoria to Beckenham Junction there is another interruption, this time by a lattice girder cast iron bridge.

Similar road bridges cross Croxted Road and Rosendale Road while the crossing of the Chatham line running between Herne Hill and Tulse Hill further west on Rosendale Road is a particularly fine semi-elliptical arch with two small pedestrian arches in buff brick with red brick dressings. This is listed Grade II.

Finally in this interesting area is the south portal of Knights Hill Tunnel with the college crest in the centre and twin ball finials on pilasters placed either side of the semi-circular arch.