I've been in 3 of the air raid shelters, the other end of tin brook outfalls under the precinct you can't climb up it
(
Paul_P http://www.Paul-hub.com,
Tue 3 Apr 2012, 17:09,
archived)
Looking at other people's reports,there appear to be a few manhole entrances, although I've no idea how accessible they'd be.
(
Happosai _,,,,_(O ; o)_,,,,
Tue 3 Apr 2012, 17:49,
archived)