15th century, remodelled in 17th century; 5-storey and attic L-plan tower house, now incorporated into Napier University (1961); pink sandstone rubble; some chamfered dressings; corbelled parapet with rounded unroofed bartizans to corners of main block, rounded at corners of wing, stone waterspouts; gabled attic storey in roof space and circular cap-house.
SE (ENTRANCE) ELEVATION: modern entrance (1958-64) accessed by concrete dog-leg stair at 2nd floor to left, tall rectangular opening with round-arched moulded doorway and heraldic carved panel; single window under doorway; blocked up basement window; single windows to 1st, 2nd and 3rd floor to right bay, single window to left of centre at 3rd floor; round cap-house with conical roof above parapet to outer left; shouldered wallhead stack to right of centre.
NW ELEVATION: advanced wing to right with off-set string course at 2nd floor, attic storey with crowstepped gable and apex stack, on return bipartite window at 2nd floor and single window at 3rd floor, pedimented dormer in attic storey; ground and 1st floor of main block obscured by modern enclosed walkway, 2 single windows above.
NE ELEVATION: main block with single window at ground floor; bipartite windows to 1st and 2nd; 2 arrowslit windows above; crowstepped gable to attic storey with apex stack.
SW ELEVATION: 2-storey modern addition; single windows to ground and 3rd floor to right; attic storey with crowstepped gable and apex stack to right, pedimented dormer to left. Multi-pane timber sash and case windows; Scottish slate roof, 2 apex and 1 wallhead stack (see above). INTERIOR: former hall (now principal's room or study) with heavily restored late medieval fireplace with nook-shafts and moulded capitals, ornate 17th century plaster ceiling with central pendant and various motifs among them reliefs of King David and Alexander the Great; former fireplace recess, lockers and serving hatch of kitchen still visible in wing; board room at 3rd floor (encompassing 4th floor) with bolection-moulded fireplace, modern gallery and transplanted painted timber ceiling of 1581 from Prestongrange House, East Lothian; some moulded stone surround fireplaces on upper floors.
Statement of Special Interest
Scheduled Monument. A later gateway is listed separately under Colinton Road, Napier University, Merchiston Castle Gateway. Merchiston Castle was the birthplace of John Napier (1550-1617), mathematician and inventor of logarithms. The castle remained largely in the hands of the Napier family, influential in Edinburgh during the 15th and 16th century, until the early 19th century when it became Merchiston Castle School. Additions made then to the castle such as large side wings were removed during the extensive restoration and refurbishment of the castle in the 1960s.