On top of that, we learned about a very clever way of keeping fresh air coming into the room. Originally we had considered the possibitlity of keeping the balcony door open while we were gone. Some re-thinking of that idea, though, brought it to a quick end. And then, just before leaving, I was playing around with the door and discovered that the door would not just swing open as doors do, but from a closed position, its top would tilt a few inches into the room, thus providing air circulation, but no possibility whatever of someone entering the room. As my mother would occasionally declare: "Man wird alt wie 'ne Kuh, und lernt immer was dazu."