For batteries. Very dangerous.

The above corridor and the follwing two photographs were taken in the basement of one of the buildings. At the end of one of the narrow corridors, the one with steps, using phone light, the boys (yes, I was too scared) found a recently concreted over wall. By recently I mean recently enough to suggest that behind the wall was a bunker, and that it was bricked off or filled in for national security reasons by the leaving party. St this point my heart was doing somersaults, but we plowed on.