More of an exploring fail to report here. Now gone so not even a lead, but thought it might still be of interest. My gf recently noticed some underground 'rooms' being uncovered on an area of Heras-fenced land in Erith recreation ground on her walk to work. Gave it a Google and turns out they were long-buried public air raid shelters. The roof was being taken off them and they were being filled in. Went to check them out less than 48hrs later and all were filled and buried except for a tiny section left at the very end. Shame as we would've had easy pickings! I don't imagine they would have been very interesting features-wjse and just typical public shelter stuff but I'm a bit gutted they went literally overnight. There's better pictures online tbh taken by a councillor from the footpath HERE
1940s - seemingly 3 sets of shelters with surface entrance steps visible
1960s - cropmarks revealing buried shelters
Shot from the surface by the mrs
