Roc Topcliffeis a Royal Observer Corps post near Topcliffe Yorkshire. It sits on the edge of a disused airfield opposite the drive to Topcliffe Manor Farm.
The mound has been cut back all round the base. This has caused the concrete apron around the access shaft to crack and detach from the entrance hatch. All surface features remain intact and fair condition with some green paint and the ventilation louvres remaining. The step and the hatch are detached. Internally the walls of the monitoring room are covered in graffiti. Remaining items include twin bunks, single bed, table, shelf, BPI mount and toilet door. The pump is missing.
Royal Observer Corps (ROC) were given the responsibility of reporting nuclear bursts and monitoring fall-out. This was archived by the construction of underground monitoring posts throughout Great Britain and Northern Ireland. These were designed to give limited fall-out protection, usually at the same location as the aircraft monitoring post.
These posts are basic, with no mains electricity or running water. Toilet facilities were basic in the extreme consisting of a chemical toilet in a small room just off the main entrance. This entrance is a 15ft shaft, dropping down to a large monitoring room, approximately 15ft by 7ft in size. These bunkers were built to a standard design. The furniture was also standardised inside the bunkers. A ventilation shaft with two louvered vents was located alongside the entrance shaft with a second air shaft at the other end of the room. Lighting was provided by a 12 volt battery located behind the monitoring room door.