West and south ranges of building at former quarrymen's barracks to north-west of Ty Mawr

Complex consists of 2 long rectangular single-storey ranges aligned north-south, linked by dry slate boundary wall on north, eastern range serving as barracks and western as cowhouse with another boundary wall and later and lower range on south forming courtyard. Cowhouse of roughly coursed rubblestone and boulder construction; some repairs and alterations in squared slate slabs; slate roof. Original cowhouse building has 4 door openings, one with boarded double doors, one stable door and 2 to right with doors missing; 3 small windows, one with C19 horizontal sliding sash; slate lintels throughout and integral end stack to right-hand end, which like the corresponding section to the east (barracks) range appears to be an extension. Cobbled path in front with boulder-lined drain. South gable end has stable door to right and a small window to left with blocked opening directly above to apex. Attached to east of the south gable end is the southern boundary wall, pierced by wide gate-way with slate menhirs as gate-posts; roof of southern range sits directly on top of continuation of wall to east.

Cowhouse has nailed A-frame trusses with single purlins; cobbled floor.