Garden walls surrounding Featherstone Castle, with gatehouse, gateways, bastions, beebole and mausoleum

The garden walls surrounding Featherstone Castle, along with a gatehouse, gateways, bastions, a beebole, and the ruins of a mausoleum, were built around 1812 to 1830 for Thomas Wallace, with the mausoleum dedicated to Lady Jane Hope completed in 1828. The walls are constructed of squared rubble in a castellated style and form extensive and continuous enclosures around a large garden and forecourt, standing between 1.5 to 2.5 metres high with flat-coped battlements.

Starting from the northwest corner, the first feature is the gatehouse, which has an L-plan and two storeys, featuring pointed openings, a shield with a carved lion (the Wallace emblem), and a parapet with a bartizan. The archway on the east side includes both pedestrian and coach arches with four-centred designs.

Next, there is a tall buttressed gateway leading into the castle forecourt, which also has a four-centred arch under a hoodmould. At the southwest corner, a low circular bastion can be found. Moving to the southeast corner, another gateway features a wide four-centred arch, with the lower section on the west side containing a pointed doorway, alongside a low circular bastion.

To the north of the southeast bastion are the ruins of the mausoleum and chapel, which include a roofless two-storey mausoleum with pointed two-light windows and a tall semi-octagonal tower, while the east wall of the chapel is located to the south. A square bastion is positioned to the north of the mausoleum, and another square bastion is set diagonally at the northeast corner.

There is also a gateway near the northeast corner similar to the earlier one, although the coach arch is now blocked. Adjacent to this gateway, a beebole faces into the garden and features four-pointed openings above projecting stone shelves. Finally, at the northwest corner, there is a tall single-storey square tower with a projecting parapet and corner bartizan.