I went in the deep shelter today. Here are my photos.
Looking up to the entrance:

Turn right at the bottom and you face certain death!

But turn left and...

Past the loos and into the main tunnel:

Looking up the second of three entrances. (blocked)

Sat in the same spot but to my right. One of the short connecting tunnels:

At the end of connecting tunnel, turn right again:

Half-way along look right and you can see down another connecting tunnel all the way to the shaft of death:

At the end is the double flight of the other blocked entrance. Looking down from small landing:

And left looking up:

The second main tunnel with entrance to unlined section halfway along on left:

Sorry that it mirrors some other pics on here. It's a lazy cut and paste from another forum where I've just spent almost two hours posting them. ;D