Going Underground

We went to London to go to a photographic tour of some disused underground tunnels.This is organised by The London Transport museum which is a charity. 
It was interesting, maybe I wasn't as inspired as I thought I might be because it was mainly dirty dusty tunnels. There were some wonderful old advertising posters, now a bit damaged but still interesting. It was noisy and a bit spooky with trains rumbling loudly just the other side of the walls.
The guide told us a bit about the history of how the Underground stations developed and how the tunnels came to be there.
At one place you could stand above the Victoria line and watch the people waiting for their trains through the ventilation shafts, as in my photo above.