Built as the stable block to Trevalyn House of 1754, with which it is probably contemporary.

A two storey building of red-brick with stone dressings, under a pitched slate roof. In plan it forms an open courtyard with walled and (later) gated entrance to the west.
The south block was the coach and stable accomodation with large, stone, dressed, arched openings with a single keystone to the first storey and alternating small thermal windows with three keystones to the second storey. The storeys are delineated by a wide stone string course.
The central block, to the east, is of three bays with the central bay projecting into the cobbled courtyard and surmounted by an open triangular pediment. In the opening of the pediment is a circular window, probably to have received a clock, and there is a later weathervane to the top of the pediment.
The north block is unfenestrated at second floor level and, to the rear, gives onto a further stable yard and the west wall of the former kitchen garden.

Internally it is largely unaltered and retains the nesting holes of a former dovecote to the rear of central entrance.
(Source; Cadw listing database) S Fielding RCAHMW 09/02/2006