The pillbox is the most familiar type of C20 defensive building. Sometimes referred to as defence posts, blockhouses or police posts. Concrete pillboxes were first used by the Russians in the Russo-Japanese War. The concept was copied by the Germans in WW1 and later by the British. The majority of WW2 pillboxes were associated with beach defences, stop-lines and nodal points. Some were sited to defend coastal batteries, airfields, radar stations and factories. More than 18,000 were built during 1940. In June 1940 branch FW3 of the War Office Directorate of Fortifications and Works issued designs for about a dozen standard pillboxes. In practice a multiplicity of designs arose. However most pillboxes consist of a basic squat, heavily constructed building, usually flat-roofed, no more than 1.98m high and quadrilateral, polygonal or circular in plan. There were one or two entrances, sometimes protected by a porch or wall. They all have a series of horizontal slits (firing loops, loopholes or embrasures) to provide interlocking fields of fire over the anticipated direction of attack. Most pillboxes were designed for rifles or light machine guns. More heavily armed examples had Vickers machine guns, anti-tank guns or Hotchkiss guns. Pillbox walls are almost invariably of concrete, sometimes with brick shuttering or stone facing {Defence of Britain Handbook, 1995, pp 79-82}.

Northumbria Gardens Trust say that the surviving ironwork including the rose-arbour may require specialist conservation advice.