Hut 9 at former Prisoner of War Camp (198) and Special Camp XI, Island Farm

Hut 9 is a low, one-storey prefabricated building dating to 1942, originally part of Island Farm Prisoner of War Camp and Special Camp XI. The structure comprises concrete wings meeting at a central brick block, with a two-storey brick tower at the rear housing a water tank over a boiler room. The roof is felt-covered concrete slate, with a shallow pitch and ridge vents, supported by paired concrete roof trusses and reinforced uprights. Projecting eaves are supported by external angle brackets attached to the uprights.

The concrete wall panels contain plain window openings, chamfered to the interior, with rudimentary concrete dripmoulds. The windows have small-pane glazing in metal frames; the original window type was a metal casement with vertical glazing bars, though the rear windows are now boarded over. A plain porch with angle pilasters and a recessed door frame with fanlight is located at the southwest gable end. Lock plates indicate external door closure.

A 1989 inspection revealed long spinal corridors running to the wings, featuring chamfered trusses creating triangular overhead arches. There are occasional openings for what were formerly skylights and metal brackets for service pipes. The hut consists mostly of two-window rooms without locks, with single high vents to the corridors. One-window rooms, with matching cupboards, adjoin the central block, which includes a further external doorway and brick partition walls. The shower room retains two-light metal-framed windows set high, and the remains of a dummy brick wall, used to conceal clay excavated from an escape tunnel. The tunnel's entrance is located within the second westernmost cubicle on the south side of the hut. The eastern end of the hut contains an unusual three-window room, and a blocked doorway with an entrance porch and lobby on the north side, opposite a locking cupboard, which may have provided privileged accommodation for high-ranking officers.

The carefully planned escape tunnel survives beneath the concrete floor of the second room on the south side. It was originally equipped with makeshift electric lighting and a ventilation pipe with a fan constructed from food tins. Timber shores were made from camp furniture. Excavated earth was carried in haversacks or concealed in pockets, sometimes molded into balls and hidden behind the false wall in the shower room. A painted image of a woman was positioned above the concealed tunnel entrance to distract guards.