Knot-garden arch at Gwydir Castle with associated courtyard walls

The Knot-garden arch at Gwydir Castle, along with its associated courtyard walls, is a notable structure built from rubble. It features an elevated wall section at the center of the southeast knot-garden wall, which includes a sandstone Tudor-arched entrance. This arch was relocated to its current position around 1828. It is believed to be connected to construction work at Gwydir carried out by John Wynn ap Meredith in the 1540s and 1550s, or possibly by his grandson, also named John Wynn, at the end of the 16th century. Given its strong resemblance to the main gate dated 1555 and the Renaissance style of the terrace arch associated with Sir John, it is most likely from the earlier period.

The arch is decorated with sculptural elements on both sides, suggesting it served as a garden or courtyard arch in its original setting. It features a chamfered design with stops at the base, and relief carvings of an eagle and a lion in the spandrels, which relate to the Wynn family arms. The arch also has double-chamfered, returned labels with carved shields at the stops, displaying the initials I and W for Iohannes Wynn. The top is capped with slatestone and includes a central 'Gwydir'-type trefoil finial on a two-stage slate-stone base.

To the southwest and northeast of the arch are slate-coped rubble walls, approximately 1.5 meters high, which date to around 1828. These walls likely mark the site of the southeast courtyard range that was demolished around 1816. The walls extend to enclose the courtyard, reaching heights of 2.5 meters to the southwest and 2 meters to the northeast. The southwest section partially incorporates the lower wall of the original barn and stable range, which was also demolished around 1816, and it ends at the junction with the gatehouse. The northeast section has a later service block added at the eastern corner and features a plain opening at its northern end, facing the house. Decorative trefoil finials adorn the coping of these walls.