The Cottage and attached walls of walled garden at Llantarnam Abbey

The Cottage and the attached walls of the walled garden at Llantarnam Abbey form a notable structure. The walled garden is enclosed by high rubble stone walls with stone coping, creating a rough parallelogram shape, and features a curved section at the northeast corner. There is a lean-to outbuilding along the north side, constructed of rubble stone and brick, which is infilled between timber posts of the original nine-bay open front. Inside, an internal wall divides the walled garden into two sections, with the southern side faced in brick.

The cottage itself is painted and rendered, featuring quoins, a slate roof with deep eaves, and windows set in double-chamfered plain reveals. The gables have small hips at the apex and large scrolled bargeboards in a 'cottage' style. It is one and a half storeys tall, designed in a T-plan with gables facing west, south, and east. There is a hipped open porch in the southwest angle supported by a square pier, which is mirrored by a hipped section in the southeast angle that has been infilled in the 20th century. The windows are 20th-century leaded glass set in rectangular chamfered surrounds.

The west gable features one single-light window above and two below, while the south return within the porch has a two-light window on the ground floor. The south gable is narrower, with a two-light window above a recessed Tudor door in a square frame, indicating possible alterations or the removal of a doorcase or porch. The east gable lacks the apex hip and has a two-light window with a hoodmould on the first floor, along with a canted bay on the ground floor that consists of one, two, and one lights, topped with a slate roof. There is also a single-storey rear wing to the north, which includes a three-light window on the east side and a lean-to structure against the eastern wall of the walled garden.