14th-15th century; additions 1810. Quadrangular-plan structure, now roofless, comprising ruins of castle to E and partially to S, remaining ranges probably 1810 when whole structure was consolidated and extended as stable court for Ballumbie House. Grey stugged rubble sandstone masonry, droved pink ashlar quoins to 1810 additions, formerly slate roof. Round angle towers to E, square angle pavilions to W. Arrow slit and cross ventilators, gun loops, small openings with chamfered margins; crenallated parapet to W elevation (partly broken down).
E ELEVATION: wall to centre; 2 horizontal window openings to lower level, 2 gun loops at mid height, 5 roll-moulded armorial panels above with coats of arms to left and centre (others empty), evidence of window openings at cut-down wallhead above. Round tower to right;
3 gun loops, 1 small opening. Round tower to left; small opening, roll-moulded window and gun loop, probable garderobe at right re-entrant angle, corbelled 4 metres from ground, later extended to ground level with chute at base, chamfered aperture to right.
S ELEVATION: wall to centre; coat of arms at roll-moulded panel to right, remains of bellcote at wallhead. Round tower to right; gun loop and blank roll-moulded panel to top. Pavilion advanced to left; arrow slit ventilator to ground floor, cross vent above.
W ELEVATION: depressed carriage arch to centre, door and window to left, door and cart opening to right; pavilion advanced to left and right each with square-headed entrances at ground floor with tripartite windows above.
N ELEVATION: paired round towers to left with gun loop and arrowslit ventilator; bay advanced to right with lean-to and enclosing livestock wall further advanced; pavilion to far right as S elevation.
INTERIOR: eastmost round towers have vaulted chambers, dovecot to SE tower; the inner skin of the E wall has been taken down and replaced by brick for stable lining; evidence of surviving early masonry at S wall; other 1810 internal walls which formed an open central court are ruinous, but openings remain evident.