Penlle'r Castell

Penlle'r Castell is the remains of a medieval castle sitting on a mountain ridge with preserved earthwork features and deep V-shaped ditches. On top of the large central mound sit the remnants of three drystone buildings that formed the defensive works.

The castle was built around 1252 by William de Braose II during his conflicts with Welsh lords and served as a frontier fortification. It shows typical Norman construction methods that were used to control conquered territory.

The name means 'castle head' in Welsh, reflecting its commanding location in the landscape. Walking around the site, you notice how the elevated position would have allowed those here to watch over the surrounding lands.

The site sits on the Mynydd y Gwair summit at about 1200 feet (370 meters) and requires a challenging walk over open terrain. There are few markings or facilities, so sturdy footwear and attention to the uneven ground are essential.

Because of its ridge-top position, the castle could watch over old trade routes that cut through mountain passes in the area. This control of passing traffic was as important to its purpose as defending against direct attacks.

Location: Mawr

GPS coordinates: 51.76912,-3.93554

Latest update: December 9, 2025 12:26