Folly, Rockfort, 154 Clyde Street East, Helensburgh

Folly, Rockfort, 154 Clyde Street East, Helensburgh, was built in 1849 and is a 2-storey and attic, 4-bay gabled Tudor revival villa with a roughly L-shaped plan. The exterior is harled with ashlar dressings and painted. It features base and cill courses, ashlar mullioned windows with raised margins, chamfered reveals, hoodmoulds, quoin strips, and decorative bargeboarded gables.

On the north (entrance) elevation, the centre has 2 advanced bays with a gabled projection. There is a projecting doorpiece on the left bay with stop-chamfered angles and a corbelled cornice, featuring a Tudor-arched doorway and fanlight, deeply chamfered and moulded reveals, and 2-leaf panelled doors, along with a modern glazed vestibule door. A window is located to the right. Above, there are 2 windows on the first floor and a small bipartite attic window at the centre of the gablehead. Recessed bays flank the entrance with a window on both the ground and first floors.

The west (side) elevation has a gabled return that is blank at ground level, with 2 windows on the first floor (one window to the right is blinded) and a small bipartite window above at the centre of the gablehead. The east elevation features a gabled return with 2 widely spaced bays on the ground and first floors, and a small bipartite window above at the centre of the gablehead. There is a single-storey flat-roofed wing abutting this side with a panelled door on the north elevation.

The north elevation includes a canted window at ground level on the outer left and a window above on the first floor. To the right, there is a 2-storey wing with gabled bays and windows arranged similarly to the main block. The sash and case windows mostly have 8 panes in the lower sash and 8 panes in the upper sash, with some replacement windows. The roof is covered in grey slate and features a fine display of tall polygonal corniced stacks arranged in groups of 3 and 4.

Inside, there is a corniced ceiling and an iron balustered stair.

Additionally, there is a picturesque 3-bay rectangular-plan folly adjacent to the walled garden to the east of the driveway. This folly is constructed of rubble with ashlar dressings and has a pointed-arch doorway at the centre of the west entrance elevation, flanked by pointed-arch windows. The folly is unroofed.