I did wonder if you knew this one, having guessed 'Hidden Bunker' - guess you must drive past this twice a day to the school and back? Well done rrrrrrichie and 3 points for you. ::7:
So not fooled by the fact that I cropped this to make the circle part look smaller than it is, so it would look something like a post. For those who don't know the building, this is actually quite large and runs down the side of it.
