Great House (Ty Mawr), Aberthin

Great House, also known as Ty Mawr, is a 17th-century gentry house designed in a T-plan layout. It features a long block facing south and a rear block at the center, with an additional structure added in the northeast angle. The house has a slate roof, diagonal stacks, and rendered walls with exposed quoins, along with stone mullioned windows.

The building stands three storeys tall and has three bays, which are accentuated by large gables that contain 2-light windows. On the first floor, there are similar 3-light windows, with additional 2-light windows positioned between them. The ground floor includes a central gabled porch, which has the main doorway offset to the left. To the right of the porch, there are two 3-light windows, while to the left, there is a 3-light window and a 2-light window. The porch features a ball finial and a Tudor arched doorway, along with a sundial inscribed with "UT HORA SIC VITA." The right gable end has a 2-light window on both the first and second floors, and a 3-light window on the ground floor. The left gable end has a 2-light window on the second floor, two single light windows on the first floor, and on the ground floor, a 3-light window and a Tudor doorway. In the northeast angle, the roof sweeps down over the added structure, which includes a 2-light window and a doorway.

Inside, the house is divided into four units on both main floors by original timber partitions, with a small lobby. The original wooden stair features three short flights and corner landings in a square well, with turned balusters, a moulded handrail, square newels topped with round finials, and pendants. The parlour to the west has a stone fireplace with a Tudor-arched head, and the east wall retains original oak panelling along with 18th-century doors. The central hall, located east of the stair, includes a fireplace with a moulded head and a chamfered beam with ogee stops. The kitchen has a wide fireplace with a Tudor-arched head and a stop-chamfered ceiling beam. The rear wing is separated from the main block by a framed partition. On the first floor, the room above the parlour features a 17th-century fireplace and framed and panelled doors, while there is a blocked 17th-century fireplace in the room above the hall. Original detailing is preserved on the upper floor, including doorways, fireplaces, and beams. Much of the original roof structure and some purlins remain intact.