In message , Neill Wood
writes
I've seen inside as well once years ago when I passed by and the door
was open. I seem to remember there was a roadsweeping vehicle in
there.
Yes, I think that one of the vehicles I saw in there was a roadsweeper,
too.

I presume that the ceiling comes down to meet the access ramp
of the underpass somewhere up ahead
Y4es but that would be quite a long way ahead, around two "bends, more
or less on the site of the former Aldwych tram station.

(I've always assumed - albeit without any form evidence) that the Subway
followed the Aldwych then turned sharp(ish) left under Kingsway?)
--
Ian Jelf, MITG, Birmingham, UK
Registered "Blue Badge" Tourist Guide for
London & the Heart of England
http://www.bluebadge.demon.co.uk