Treleddyn Uchaf/Upper Treleddyn, including Garden Walls with Crosshead

Treleddyn Uchaf, also known as Upper Treleddyn, is a two-storey building from the 18th century, featuring whitewashed roughcast walls with raised cement dressings and slate roofs. The structure has a double-depth plan with a valley roof and four gable stacks. The front facade has three windows, which are 12-pane sashes, with the central first-floor window possibly being the oldest due to its thicker glazing bars. The windows have painted slate sills and plain raised shouldered surrounds. The entrance is a centre 2-panel door with an overlight, set within a whitewashed flat porch that has a moulded cornice and a painted wood Tudor arch.

The west end has paired gables with two loft windows and a ground-floor lean-to that features a 9-pane sash window on its front end. The east end mirrors this design with similar paired gables and loft windows. The rear wall is made of whitewashed rubble and includes a long 18-pane stair light at the centre, flanked by 12-pane sashes, all with painted stone voussoirs. There is also a 4-pane sash window on the ground floor to the left.

The front garden is enclosed by low rubble walls with a timber gate, and there is a splayed carriage entry to the right that features half of the original head of a Cross in St David's. Inside, a fine staircase with four dog-leg flights leads up to the attic, showcasing a painted wood 'Chinese Chippendale' openwork balustrade and a thick ramped handrail. The interior includes 6-panel doors and renewed fireplaces. The northwest room on the ground floor has a notable wall cupboard with fielded panelled doors, where the upper pair features an arched panel and a semi-circular recess for a serving hatch, topped with a cornice. The northwest room on the first floor once had a circular painted panel on the ceiling, which was said to depict royal arms and a cherub, but was accidentally destroyed during later 20th-century renovations.