Keys in room boxes can be seen behind the reception desk but hard to count accurately, and in any case unreliable indication as presence of key may mean either that the room/flat is unoccupied or that the occupants have gone out. We make half hearted efforts to go out in the evening and check for lighted windows, but laziness tends to prevail, and anyway people could be out for the evening or have gone to bed early. Then it occurs to us that closed curtains in the daytime are actually a much better indicator. The maids normally leave the curtains drawn in empty flats. Presumably in an effort to prevent fading, although all that is likely to fade in these rooms is the curtains themselves. Pursuing this method leads us to conclude that of the twelve flats visible from the front of the hotel only ours and one other are currently occupied.