Lydiard Park

Lydiard Park is a mansion dating back to the medieval period, with significant alterations in the 17th century and a major remodelling between 1745 and 1749 (as indicated by a date stone in the attic). The work in the 18th century is attributed to Roger Morris, possibly under the direction of C. Hussey, for John, 2nd Viscount St. John. The building is constructed of stone, with ashlar Bath stone used for the 18th-century remodelling, and features stone slate and lead roofs.

The original structure appears to have been a hall with cross wings, which were extended in the 17th century to form an H-shaped plan. The mid-18th century remodelling focused on the south and east fronts, creating a central hall and interconnecting state rooms, along with a library, dining room, and drawing room. The facade is strictly Palladian, inspired by Houghton Hall. It is a two-story building, with three-story quoined corner towers. The central three bays project forward, crowned by a pediment enclosing the St. John family arms and motto "SANCTUS IN TERRA BEATUS IN COELO." A Roman Doric doorcase, pedimented and with a pair of glazed doors and a lobed fanlight, provides the main entrance. The ground floor windows are predominantly 16-pane sashes, while those above are 9-pane, all of which have been restored. Ground floor windows are capped with pediments. The third and ninth windows on the front elevation are distinguished by flat cornices. The east elevation has seven bays, with window cornices only at the centre.

Inside, the mansion boasts seven state rooms of exceptional quality. These rooms are characterised by six-panel doors set within broken and lugged doorcases with carved pulvinated friezes, and plaster ceilings. A flying stair is located to the rear of the hall, featuring three twisted balusters per step. First-floor rooms have dentilled cornices. The Left Ante-room features a painted marble fireplace with an open pedimented overmantel. The library retains original bookcases that project forward with broken pediments and busts, and has an open-pedimented fireplace with marble columns and a coloured marble frieze, with a geometric panelled plaster ceiling. The Hall displays a coved ceiling and a limestone chimneypiece with tapered pilasters and masks. The Dining Room incorporates Ionic columns to divide recesses, a Rococo ceiling, and a garlanded overmantel with a broken pediment. The Parlour has a rectangular panelled plaster ceiling with carved fruit on the joists, along with a Kentian carved Carrara marble fireplace supported by herms in profile, along with mirrors. The Ballroom features recesses divided by Corinthian columns, a Rococo ceiling, and a dentilled cornice. The fireplace includes ornate Corinthian pilasters and a broken pediment with a basket of flowers. An Ante-room is distinguished by a coffered apse with a small marble fireplace, and contains 17th-century painted glass in the apse window, likely the work of Abraham van Linge.