11 The Diamond, Ballycastle, Co Antrim, BT54 6AW

11 The Diamond is a three-bay, three-storey building with a basement, dating from the 1990s. It replaces an earlier property, which first appeared on an Ordnance Survey map from 1857, and was destroyed by fire in the 1990s before being completely rebuilt with a new design. The building fronts both The Diamond and Ann Street.

The Diamond frontage, from the right, features a ground-floor double-hung, 12-pane sliding sash window with painted archwork surrounding it. Next is a shopfront with a square-headed door, a large window divided into three vertically round-headed panes, flanked by fluted pilasters, and a deep name fascia with cornice and painted lettering. The first floor has three double-hung, 12-pane sliding sash windows, while the second floor has three double-hung, six-pane sliding sash windows. A half-round gutter and single downpipe are present. The smooth, rendered walls are painted, and quoins are picked out in colour. A basement area with steps leading to a pizzeria entrance is located below the right-hand window, enclosed by cast iron balustrading.

The Ann Street frontage is two bays wide, also with a ground-floor shopfront, this one without a door, and featuring a large window subdivided into four vertically round-headed panes with a similar name fascia. The first floor has two double-hung, 12-pane sliding sash windows, and the second floor has two double-hung, six-pane sliding sash windows. The walls are smooth, rendered, and painted with quoins picked out on each side. The building is well situated in relation to The Diamond, with a broad paved area in front, though partially interrupted by a railing. The Ann Street frontage aligns with the building line and contributes to a terrace that begins with No. 1 Ann Street.

The building is within the Town Parks townland and was designed by Smyth & McMurty, although their involvement is currently unconfirmed. The architect remains unknown. While within a conservation area, the building has neither architectural nor historical merit.