Frodsham AAOR â Subterranea BritannicaSubterranea Britannica is a society devoted to the study and investigation of man-made (including Nuclear Bunkers) and man-used underground places.Written by Nick Catford on 03 December 2001. The Frodsham AAOR was in 4 Group, 79 Brigade serving the Mersey Gun Defended Area (GDA). It is of the standard design built in the early 1950’s with both floors above ground. The main entrance is into the lower https://www.subbrit.org.uk/sites/frodsham-aaor/