In 1972 a bunch of us third gaders in Augsburg Germany discovered that our elementary school, formerly a nazi military building, had a network of tunnels underneath the military base. Every day after school when as far as our parents knew we were "bike riding" on the secure military installation, we instead explored further and furthe into the tunnel system until one day we went so far that we were lost, and our flashlight batteries expired, and we spent twenty hours in the cold darkness until the search dogs led the MPs to our scared little group.