Northumberland was seen as a likely area for any sea borne invasion due to it’s low coastline and relative lack of population and thus had many defenses built. As well as several stoplines consisting of pillboxes, usually about 1 mile apart there were numerous coastal defenses which were also pillboxes of varying types, beach scaffolding, anti tank blocks, ditches, gun batteries and beach lights.
Many of the buildings were constructed in reinforced concrete and are therefore still in good condition today. Although there is one not far from Bamburgh castle which appears to have split in two! Most metal structures have not fared so well after being neglected for over 60 years.
There were also several airfields in Northumberland at least two of which had extensive defensive rings. RAF Ouston still has a fascinating array of different types of pillbox surrounding it and much of the airfield is still extant. The buildings are still in use as Albermarle barracks. RAF Acklington has at least 4 pillboxes surviving although the buildings are now a prison and much of the rest of the site has been destroyed by open cast mining.