The map does not show any windows. However, you can guess there would be some for each room. The hill you are on appears to encircle the clearing, like a low wall. From what you can see across the depressed clearing, the roof of the building has caved in and there are several windows at each level in each side of the building - you are facing a corner of it. A raised roadbed connects the left side of the building to a portion of the wall-hill about two hundred yards to your left. It would be fairly easy to clamber along and up the rubble to get to the near end of the roadbed. You can see that the roadbed runs about two thirds of the way across the clearing, and has three bridges along its length of about three hundred yards. At the end of the roadbed nearest to the building there is kind of a ledge with big doors in the building that would open onto the ledge. You can guess that's the Entrance Hall shown on the map.