Garden Bridge, Tulloch Castle

The Garden Bridge at Tulloch Castle is a 16th-century square tower that has undergone various alterations and extensions from the 17th century to the early 20th century, particularly to the north and east. Notable modifications include extensions, restoration, and improvements by A Maitland and Sons in 1891, and further alterations by Sir Robert Lorimer between 1920 and 1922.

The tower features harled walls, with rubble used elsewhere and ashlar dressings throughout. It has a southwest tower with heavy boulder footings, a chamfered southwest angle at the first floor, gun loops, and a later Venetian window on the first floor of the west elevation. The south elevation of the tower has two enlarged and symmetrical windows on each floor, while the northwest drum stair tower retains original small windows. The tower and stair tower are topped with later corbelled and crenellated parapets.

In 1891, a three-storey, three-bay wing was added to the east, flush with the tower, featuring a large two-storey canted bay window. Sir Robert Lorimer raised this wing from two to three storeys, with the three upper windows extending through the wallhead in ornately carved pedimented gables, with the center gable dated 1920. The east crowstepped gable-head also features similarly carved detailing. The east elevation of the wing extends three storeys and has five bays, with five pedimented gabled dormers that rise through the wallhead, matching the detailing of the south front. A Venetian window is located in the southeast gable.

A square projecting porch, which is heavily corbelled and parapetted, masks a corniced and moulded lugged architraved doorpiece that features a heavily panelled and studded door designed by Lorimer. A large round-headed archway with a hoodmould leads to the service wings at the rear. The building has multi-pane and two-pane glazing, corniced ridge and end stacks, crowsteps, and a slate roof.

Inside, there is a vaulted basement and a remodelled first-floor hall that includes the original great fireplace and an ornamental plaster ceiling from 1920 to 1922. The interior also features later 19th-century pine panelling and a wide balustraded staircase. There are arched and segmental-headed tunnel entrances that carry a path linking the east and west parts of the garden.