Penllyn Castle

Penllyn Castle is a two-storey house, likely constructed from local rubble stone, but mostly covered in pebbledash, with stone dressings and a hipped slate roof, along with significant leadwork. The rectangular building has its shorter side facing south, which features the main entrance.

The south front has rounded corners, a cyma recta band at the first floor level, a modillion cornice, and an embattled parapet. It includes five sash windows with glazing bars, featuring 6 over 9 panes on the ground floor and 6 over 6 panes above. There is a central flat-roofed porch made of green Bridgend limestone ashlar, with a pointed head outer opening, decorated in the style of Batty Langley.

On the east front, there is a two-storey bow at the south corner and a tall square rubble tower with battlements in the center. The west elevation, which is longer and also has five bays, features a tripartite sash window with 6 over 6 panes in an elliptically headed recess in the first bay from the left, with a matching 6 over 6 sash above. The next two bays are set forward, all with plain 6 over 6 sash windows. The fourth bay has a flat-headed tripartite sash with a plain 6 over 6 sash above it. The fifth bay is a shallow two-storey bow with a 6 over 6 sash window on each floor. The exterior is topped with five tall Victorian chimney stacks featuring paired and tripled circular flues.

The north side connects to an L-shaped Victorian range that includes a tall battlemented tower with a clock, originally built as a water tower. It is believed that the house connects to the remains of the medieval castle, although this was not confirmed during the resurvey in October 2003.

The interior was not accessible during the resurvey, but it is reported to contain classical style rooms from around 1860, featuring Louis Quinze style fireplaces and an open-well top-lit semi-circular cantilever staircase. The rooms also have contemporary panelled shutters on the west and south fronts.