Gatehouse, Borthwick Castle

Borthwick Castle, including its outer walls and gatehouse, dates to circa 1430 and represents an extremely good example of a complete 15th-century Scottish keep. Built by Sir William Borthwick following his purchase of the estate from the Hays of Lochorwart, it was constructed after he received a royal charter on 2 June 1430. The castle replaced the now-demolished Catcune Castle as the Borthwick family seat.

The building forms a U-plan keep within a courtyard. The main block rises three storeys above a basement, with two wings extending six storeys above their own basements. The structure is constructed of grey coursed ashlar with a splayed base course and chamfered reveals. The machicolated parapet features bartizans positioned at the external angles. The outer walls, gatehouse, and parapet underwent restoration by John Watherston and Sons around 1892.

The west elevation is slightly asymmetrical, comprising three bays with two projecting wings to the outer left and right. The outer bays show irregular fenestration with blank returns on the inside, while the central recessed bay features roughly regular fenestration. The south elevation displays irregular fenestration. The east elevation also has irregular fenestration but is notably marked by missing stonework on the upper floors; the parapet and angle bartizans have been removed from this side.

The north elevation is asymmetrical and contains a round-arched doorway at ground level leading to the basement, fitted with a boarded timber door. A quarter-turn stone stair rises to the principal entrance at first-floor level. A three-storey square-plan harled tower stands at the angle of the stair. To the west of this tower is a modern single-storey addition of four bays in snecked rubble with a slate roof. A round-arched doorway at first-floor level features a boarded timber door with decorative ironwork; above it sits a blank niche. The elevation displays irregular fenestration, and an iron balcony adorns a large window on the upper floor to the left.

Throughout the building, slit windows are present, some enlarged. The main block is roofed with stone slabs, whilst the wings and cap houses behind the parapet are covered with grey slate, these roofs having been restored between 1892 and 1914. Various ashlar chimneys stand behind the parapet.

The outer walls and gatehouse form a roughly triangular enclosure, largely rebuilt in 1892 using rubble with semi-circular coping. The base of the wall to the west is original, featuring wide-mouthed gun ports. A circular tower occupies the south-west angle; its original understoreys contain horizontal gun ports, while the upper storey dates to 1892 and is accessed via steps within the courtyard. The round-arched gateway with machicolated parapet, adjacent to the south-west tower on the west wall, dates to 1892 and was rebuilt on the site of the original. The wall sweeps down to the south and is interrupted by a doorway with an iron door to the north.

The interior preserves its original form remarkably well. The main range contains three transverse tunnel vaults at its base, comprising the basement and upper basement. Above these sits a pointed vault forming the Great Hall, which features a 15th-century wall piscina with a carved canopy to the right of the north screen wall. A round-arched doorway to the left leads to a stair ascending to an 1892 timber mezzanine. The south wall contains a fireplace with a carved lintel supported by double engaged columns with carved capitals; an armorial shield set in a pyramidal hood bearing the date "1913" is mounted above. A depressed arched buffet or seat recess with a 15th-century carved canopy is positioned to the left of the west wall. Above the great hall, a tunnel vault is divided into two storeys: the lower comprises a drawing room with a grand fireplace and a chapel featuring a round-arched oratory recess containing a locker and piscina; a vaulted room occupies the upper storey. A stair in the north-east corner of the main range provides access.

The north and south wings contain turnpike service stairs set within the walls of the re-entrant angles and were primarily designed for service quarters and bedrooms. A well lies in the basement of the south jamb, whilst the north jamb housed a prison with a kitchen above it.

Sir William Borthwick's acquisition of the estate, including the Mote of Lochorwart, replaced the earlier Catcune Castle. It is believed that a mote hill originally stood on the site but was levelled to accommodate the present castle, which was built upon the site of the bailey. Around 1892, the gatehouse was raised by one floor because the original gate was too low for modern vehicles. The castle once featured a 17th-century oblong dovecot projecting from the south-east angle of the curtain wall, and a tower stood midway along the south wall. These structures no longer exist. The north section of the courtyard presumably contained stables and outbuildings.

Although the interior remains largely unaltered, the rooms, particularly the great hall, would originally have been plastered and decorated with colourful painted allegorical scenes and motifs. Inscriptions included "ye tempil of honour" and "ye tempil of religion", which no longer survive.

The castle's unusual U-plan provided advantages beyond mere additional accommodation. In 1567, Mary, Queen of Scots and Lord Bothwell fled to Borthwick from Holyroodhouse following his killing of her husband. When their hiding place was discovered, she reportedly escaped disguised as a man. The large gash visible in the east wall has several possible explanations: simple decay seems unlikely given the excellent condition of the remainder of the building; alternatively, around 1650, the 10th Lord Borthwick is said to have refused Oliver Cromwell's request to leave the castle, and the damage may result from military action at that time. This incident evidently caused the castle to be abandoned by the Borthwick family until 1810, when J. Borthwick of Crookston purchased it. Systematic restoration did not commence until the end of the 19th century. In the 20th century, the castle's secure nature proved valuable when it served as a repository for national treasures during the Second World War. Since 1973, the castle has functioned as a hotel.