Castell-y-mynach

Castell-y-mynach is a Grade II* manor house comprising a two-storey L-shaped structure of limewashed rubble with Welsh slate and stone tiled roof. The main range faces the garden and features overhanging sprocketed eaves and decorative bargeboards. Ridge stacks with cornices crown the main range, while a tall square rubble stack with off-sets rises from the rear eaves.

The upper garden-facing frontage displays a 4-window range of horned sashes to the first floor, some with cambered heads, two set beneath earlier hoods. The ground floor has two casement windows flanking a stable-type door with hood. To the right, a small window sits in a chamfered stone surround, followed by a wide blocked moulded stone archway with 4-centred head and two sunk quadrants. At the far right end is a long multipane staircase window with keystone. The left end features a stone-tiled outshut with boulder footings and catslide roof extending from the gable, which has a shallow corbelled first-floor external stack with a projection at its base.

The rear elevation of this wing includes a small stone window with trefoil head, spandrels and hoodmould at lower level, and above it a blocked 3-light window with moulded mullions. The next bay contains a horned sash to the first floor and small casement below. A blocked 4-centred archway with chamfered moulding now incorporates a horned sash window. Above this is a 2-light window with moulded mullion, and to the right a larger 4-light leaded casement with moulded mullions. At ground floor level a small cambered-headed casement stands to the right of the blocked arch, with a small sash window in stone surround to the left.

The lower cross wing has a slightly lower ridge and half-hipped roof with end external stacks and a lateral brick stack. Its inward-facing side displays a 3-window range of unequal casements with voussoirs, keystones and narrow sills at first floor level, sash windows to the ground floor (paired to the left), flanking a wide central doorway with similar heads. The gable end facing the garden has a wide full-height external stack. The outward-facing elevation shows an unequal range of 6/6 horned sashes, some with cambered heads, a centre-left doorway with margin-glazed overlight, masonry stepped forward to the right with an arch above the window to its right, and a blocked feature at ground floor left.

The interior retains significant early features. The ground floor of the south wing preserves chamfered beams dividing the ceiling into compartments, an early 18th-century doorframe and overdoor, and two carved and painted wooden achievements—one of the Stuart Royal Arms in strapwork frame and one of the Mathews coat of arms. A former cross passage survives in the west bay, and at the other end a doorway links the range with a gatehouse. One wall of the staircase well displays a wallpainting dated 1602 showing a black and white pattern in decorative borders. Two of the upper rooms retain parts of an open timber roof with moulded arched principals and two moulded purlins.

The main upper chamber above the medieval hall contains a wallpainting depicting figures holding a scene of ships with a tapestry draped on the parapet. The complete arch-braced roof of the former open hall survives with fine moulded principals and purlins and embattled wallplate.