A mid to late 19th century barn, which is shown on the 1st edition Ordnance Survey map surveyed in 1887. Glynllifon was the seat of the Wynn family and Sir Thomas John Wynn became the 1st Lord Newborough in 1776. The house was rebuilt after a fire 1836-48 by Edward Haycock, architect of Shrewsbury.

A tall, open-sided, 6-bay, estate hay barn built of honey-coloured stone with red brick dressings under a half-hipped slate roof. A tall opening on gable end faces the mill, and has a slate lintel with patterned ventilation holes above. The openings to the right hand (north-west) side have been partly filled in but the original effect is retained to left hand side where they remain open to the full-height of the elevation. Here there is an added corrugated lean-to. The tall opening at the south-west end has also been partly filled in but retains diamond patterned ventilators above. Inside are King-post trusses with two tiers of purlins.
(Source; Cadw listing database) S Fielding RCAHMW 21/11/2005

The barn is represented by a dashed line only in 1889 (1887 survey).

Associated with: Glynllifon mansion (NPRN 26526) and grounds (NPRN 86377).