There's a Light in the Window

Building "B" in Aerial Photo, Floor 2(I think)

 

Remnants of the old heaters that were hooked up to the steam pipes are still littered about the place. I think this photo was taken on the second floor of the main building, looking at a rectangular area open to the sky that was built into the center of the second floor - not sure why, possibly to bring daylight into the center of the building, but it seems like skylights would have been an easier way of getting that. You can see this area on the aerial photo, a dark black rectangle just to the left of the red letter "B".

Done