23-25 South Harbour Street, Ayr

23-25 South Harbour Street in Ayr is an early 19th-century, three-storey and attic tenement building with a rectangular plan, located on a corner site. It features a single-storey addition on the outer right. The building is finished in painted render, with squared and snecked red sandstone on the outer right. Architectural details include an eaves course, cornice, and strip quoins, along with painted margins around the window openings.

On the northeast elevation, there is a timber door at the central entrance, with a boarded entrance to the right and flanking boarded openings. To the left, there is a recessed shop entrance with a modern glazed door and flanking shop windows, along with a shopfront fascia above. The first and second floors have regular fenestration, although the upper panes are blocked at the first floor in the centre and right. The attic features canted dormers on the outer left and right. The single-storey, five-bay section on the outer right has a timber door in the penultimate bay and boarded window openings in the remaining bays.

The southeast elevation, facing Fort Street, has a single opening at the ground level on the outer left and single windows at the centre and right on the first floor. The predominant windows on the northeast elevation are plate glass timber sash and case, while the southeast elevation features 12-pane windows. The roof is covered in grey slate, with stone skews, corniced gablehead stacks, and both circular and polygonal chimney cans.

The interior was not seen in 1998.