Former British Ironworks office and foundry quadrangle

The former British Ironworks office and foundry quadrangle dates back to the 1820s or 1830s and is constructed of coursed sandstone with Welsh slate roofs, although some sections have been partially lost or replaced with corrugated iron. The quadrangle is a largely enclosed arrangement of buildings, with the north-east pavilion being two storeys high and rendered, while the rest are single-storey.

The front range, facing northwest, originally comprised two square pavilions with pyramidal roofs, connected by a lower range. The right-hand pavilion appears largely unaltered and features ashlar quoins, an eaves band, and window and door surrounds, with coursed sandstone in between. Surviving windows are wooden sashes with sixteen panes, though some were lost in a fire. The main elevation has two windows and a central doorway with a flat hood, while the north-west elevation has three openings, one of which is blocked. The left-hand pavilion mirrors the ground-floor detailing, but has been altered around the turn of the century, including a fanlight above the doorway. The original eaves band now functions as a string course and the walls have been rendered. The roof is hipped with slate and includes chimney gablets. The upper storey has tall casement windows arranged in four bays, with a narrow central window on each outer side. The connecting block is built of rubble sandstone with dressed quoins and window surrounds. The windows are evenly spaced and have shallow segmental arches, stone cills, and metal small-pane frames or timber cross frames with leaded light panels.

The south-west elevation has seven windows facing outwards and four facing inwards, while the south-east elevation, built into the slope, has seven openings outwards and inwards.

The complex has suffered extensive damage since being listed in 1994, particularly in the northwest corner which is now in a severely damaged state.

Inside the two-storey office building, a central hallway and staircase lead to four rooms on each floor. Corner fireplaces are present in the rooms to the south-west. The fire-damaged pavilion displays a magnificent pyramidal roof structure of massive timbers, creating a large open space interrupted by later inserted walls. The trusses are of king post design with linked trusses at right angles. The workshops also feature king post roof trusses, creating large open spaces. Some areas retain cast iron floor plates characteristic of foundry buildings, and large openings in the south-west wall were made to allow for the casting of molten metal. An air furnace is a separately scheduled Ancient Monument. Evidence suggests that casting pits and remnants of a waterwheel or small steam engine, once used to power workshop machinery, may remain below the floor level.