Entrance Arch, North Lodge, Castle Grant

North Lodge at Castle Grant is a baronial gate lodge built between 1863 and 1864. It features two storeys over a raised casement and has a projecting wing at the south, creating a T-shaped plan. A drum tower projects at the northwest, adjacent to the railway track. The building is constructed of rubble with tooled ashlar dressings.

Access to the lodge is provided from the railway track through a moulded doorway in the drum tower, as well as via a forestair that is concealed by a quadrant wall in the south gable of the wing. The north elevation has a pair of windows that break the wallhead beneath crowstepped gablets, while similar windows flank a small stair turret that is corbelled out at the first floor. A continuous string course connects the cills and hoodmoulds at the first floor. The drum tower features a small dormer and has fishscale slating on its bellcast conical roof, which is topped with a cast-iron weathervane.

The lodge has 8-pane glazing, crowstepped gables, coped end stacks, and slate roofs. The railway bridge, also built in 1863-1864, is a single span made of coursed rubble with tooled ashlar dressings, featuring an ashlar skewed arch ring and a crenellated balustrade around the terminal end buttress piers, which have shallow circular caps.

The entrance arch consists of a tall, round-headed tooled ashlar granite archway with a shaped wallhead, flanked by dummy crenellated bartizans that are corbelled out on each side. A coat of arms is positioned at the center of the arch, which is connected to the lodge by a coped wall with a doorway. There is further similar walling extending to the south.