Summerhouse And Outbuildings, Walled Garden, Blackadder House

The Walled Garden at Blackadder House dates from the later 18th century and has undergone alterations since then. It covers approximately 3 acres (7.4 hectares) and is located to the west of the former Blackadder House. The garden is enclosed by very tall sandstone rubble walls, featuring a coping wall and a brick interior wall, with the southern wall made of sandstone rubble on the inside. The western wall is no longer standing as of 1996.

At the center of the northern wall stands a two-storey, octagonal-plan summer house constructed from finely droved ashlar with polished ashlar recesses. It features a deeply droved and fluted ashlar band course at cill-height. On either side of the summer house are monopitch rubble outbuildings, also with droved ashlar dressings. Lean-to glass houses are situated on the southern side of the northern wall, although they are now partly in ruins as of 1996.

The summer house includes a band course at cill-height, a cornice, and a blocking course with a raised tab at the center of each elevation, creating a castellated effect. There is a panelled door on the ground floor to the north with glazed upper panels, and a bipartite door to the south with seven panes and a panelled lower section leading to the glass house, featuring a fluted timber surround and a radial fanlight above. An ashlar forestair with a wrought-iron handrail leads to a nine-flush panelled door on the northeast side at the first floor. Each elevation on the first floor has a round-arched recess with a round-arched opening, which is blinded to the west.

The interior of the summer house was seen in 1996 and features a lath and plaster ceiling, but is in poor condition.

Three timber-framed glass houses remain in place as of 1996, with glazing except for the house to the west. The upper vents are operated by a series of cast-iron cogs and shafts, and cast-iron floor grates are present in the central house. There are glazed partitions between the houses, each with a glazed door.

The outbuildings are generally in poor condition as of 1996 and have a slate roof, with a boiler still in position.

To the south wall, there are gatepiers made of droved ashlar with a ball finial on the western pier. Wrought-iron gates with ornate flanking panels and cresting above complete the entrance.

To the southeast of the walled garden, there is an enclosure with a rubble, coped wall and cast-iron fleur-de-lys headed railings. A similar gate is located at the southeast corner, and this area may have been used to keep animals.