Thomas Brown, 1847; restored and converted to museum and offices 1994-6, Stirling District Council architects, main contractor Ogilvies. 3-storey and basement, 7-bay, V-plan prison with crenellated parapets and large round tower to W. Dark whinstone squared and snecked rubble with contrasting droved ashlar dressings and quoins. Round- and segmental-headed openings; hoodmoulds, stone mullions, concave-moulded and chamfered arrises.
E (ENTRANCE) ELEVATION: symmetrical. Centre bay with steps up to deeply chamfered and hoodmoulded round-arched doorway, 2-leaf panelled timber door with decorative-astragalled fanlight, hoodmoulded windows in flanking bays, 3 round-headed windows above and parapet over with centre bay extending into 2nd floor tower with hoodmoulded, round-headed tripartite window below machicolated parapet. Flanking single storey bays each with window and parapet, and segmental-headed window to each floor of recessed face behind. Full-height, parapetted outer bays with segmental-headed openings, door to ground at left and window to right, window to each floor above in machicolated, recessed panel.
ROUND TOWER: 4-stage engaged tower to centre bay of W elevation with small round 3-stage tower to NW corbelled out from 1st floor, and 3-stage polygonal tower to E rising above 3rd stage. 3 segmental-headed windows to 1st stage (raised basement) and to 2nd stage (ground floor); 3rd stage with 3 windows to 1st and 2nd floors connected by narrow vertical panels and continuous hoodmould forming rounded windowheads at 2nd floor; 4th stage with 3 glazed oculi below machicolated parapet. Small corbelled tower with 2 gunloops to 1st stage, 1 to 2nd stage and further smaller loop to 3rd stage with machicolated parapet. Blind polygonal tower with crenellated parapet.
W ELEVATION: 13-bay elevation with round tower (see above) to centre and segmental-headed openings. Bays to right of centre with 4 small windows (cells) high up in raised basement, regular fenestration and parapet above; 2 slightly higher advanced outer bays with similar fenestration. Bays to left of centre mirror those to right.
N ELEVATION: raised basement with round-headed doorway and 2-leaf panelled timber door to left, 3 close-set round-headed windows to centre, and each floor above with 3 windows to centre (as above) those to 1st and 2nd floors in machicolated panel, and narrow round-headed lights to flanking bays.
S ELEVATION: mirrors N elevation.
Multi-pane glazing throughout, some windows retain bars. Graded grey slate. Cast-iron downpipes with decorative rainwater hoppers.
INTERIOR: all cells to W. Basement cells retained with Victorian jail and military prison detail; cantilevered galleries above converted to offices; central beehive panoptican and former Governor?s office with corbelled viewing bay.
BOUNDARY WALLS, GATEPIERS AND GATES: St John Street entrance with crenellated squared and snecked rubble boundary walls and square-plan, crenellated ashlar gatepiers each with gunloop to E and sentry hole to W, cast-iron gates. Inner wall with segmental-headed archway, crenellated parapet and cast-iron gates flanked by semicircular-coped rubble walls. Further high boundary walls to N, S and W with triangular-plan outbuilding to SW angle.