The monument consists of Rait Castle, a rare example of a small masonry hall-house probably dating to the late 13th/early 14th century. The hall-house is surrounded by the remains of outbuildings and a building to the SE may have been a chapel mentioned in contemporary records. The site is heavily overgrown, and apart from the hall-house the remains are difficult to identify. The monument was originally scheduled in 1959. On this occasion, an indistinct and inadequate area was scheduled: the present rescheduling rectifies this.
The Thanedom of Rait is first recorded in the year 1238 and its earliest recorded lords took their names from their manor; Sir Geirvaise de Rait and Sir Andrew de Rait. During the Wars of Independence Sir Geirvaise and Sir Andrew supported Edward I and probably were responsible for the castle's construction. Despite supporting Edwardian occupation the de Raits appear to have held on to the castle and lands of Rait until 1404, when the Sir Alexander Rait fled the area after slaying the Thane of Cawdor. In the 15th century the lands of Rait were held by the Mackintoshes. The last recorded reference to a castle on this site was in 1596.
The hall house consists of an oblong first floor hall raised on unvaulted cellarage, and is constructed of whinstone and granite rubble brought to courses, with red sandstone dressings. The hall measures approximately 16.5m by 6.7m and up to 11m in height, with walls nearly 2m thick. A round tower projects from the SW corner and has a corbelled domed ceiling. There is a latrine tower which projects nearly 4m to the S of the W elevation and is 2.5m wide. The hall house was entered from a first floor doorway through the S wall. The doorway is particularly fine, consisting of an outer and inner pointed arch with a hood moulding. The door was protected by a portcullis and then by a timber door secured by a draw bar. The hall is lit by lancet windows divided into three lights by a branched mullion. A fireplace, the only fireplace within the hall-house, is situated at the W end of the S wall. The positioning of the windows and the fireplace suggests that that first floor was either divided into a hall, an outer chamber with fireplace and latrine, and inner chamber within the round tower, or that the upper area of the hall had a broad dais, with the lord's private accommodation situated within the round tower.
There are slight traces on the north side of the castle suggesting an enclosing ditch. Between the hall and the knoll to the south is the courtyard, the south wall of which incorporates a steep, smooth granite outcrop. The wall is constructed of similar materials to the hall-house and stands to a height of 3m and 1.5m thick. The detached building SE of the hall-house is possibly the chapel of St Mary of Rait, or Hermit's Chapel. In 1343 Nicholas the Hermit was in occupation and records exist of a chapel c.1189-99.
The area to be scheduled includes the hall-house, the associated courtyard, buildings and possible chapel, and a surrounding area, in which traces of associated activity may be expected to survive. It is quadrangular in shape with maximum dimensions about 93m from its northernmost to its southernmost point, and 93m transversely, as marked in red on the accompanying map.