The hay barn was built in the late 1850s, probably by the architect J W Poundley, is one of the later buildings making up Leighton Farm, the model farm of the Leighton Estate which was aquired by John Naylor in 1846-47.

The haybarn comprises a large aisled barn with vent ridge, constructed of brick with slate roofs and coped gables on moulded kneelers. The building has a three-bay west front facing onto the road, the central bay being slightly advanced, and has three stepped, round-headed lights with louvres above a large round-headed doorway, which has stone imposts and a boarded gate in vertical runners. In each aisle is a blind round-headed window. The east gable is similar but with breathers in a lozenge pattern in the outer bays. The side walls are mostly weatherboarded, while the vent ridge has louvred panels (with occasional glazed panels) on the north side and corrugated asbestos-cement sheets on the south side.

Internally the barn is divided into nine bays by open timber-framed partitions which also support a granary loft. The central aile was originally furnished with tram rails, along which carts carrying the hay ricks could be brought from the rick yards. Either side of the aisle are brick plinths with protruding slate courses, designed to impede rats climbing their way into the stored hay.

(Source; Cadw listing database & RCAHMW survey) RCAHMW 10th Novemeber 2008