70 Montague Street, Rothesay, Bute

70 Montague Street is an early 19th-century, three-storey, four-bay tenement that forms the end of a terrace. The building features a rectangular plan and includes a shop and licensed premises on the ground floor. It is constructed from cherry-cocked grey rubble sandstone with heavy pointing, and has droved quoins along with droved long and short red rubble sandstone surrounds to the polished upper openings. The building has projecting cills and corniced eaves.

The south elevation features a replacement timber door in the central bay, topped with a quadripartite fanlight, and the licensed premises are located to the right. To the outer left, there is a replacement glazed timber door for James McIntyre Butcher, with a projecting sign on a cast-iron bracket. The first and second floors are regularly fenestrated across all bays.

The ground floor has replacement windows, while the first and second floors have boarded openings. The roof is covered with grey slate and has a coped harled apex stack to the west, although the cans are missing. Inside, extensive tiling is still visible behind replacement panels at McIntyre's Butchers.