nifty Hogwarts facts/which floor?

[Steve Bates]

No: HPFGUIDX 3071

<I'm trying to create a concise list of which rooms are on which 
floors and this whole first floor/ground floor thing keeps getting in 
the way...>

Might not be your only problem.  Hogwarts seems to experience a less 
dramatic effect of "shifting locations" similar to what happens to 
the rooms in the ID Headquarters in PoU, which continuously and 
randomly change their relative position.  It happens much less 
frequently, haphazardly, or confusingly at Hogwarts, but wasn't it 
mentioned in the first book that different staircases lead 
differently places on different days of the week, and things of that 
sort? This might help protect the common rooms from people in the 
other Houses: only the people in a particular house would know the 
pattern of locations their common room folows.  Which helps explain 
why Ron and Harry had to be shown where the Slytherin common room was 
in CoS.  Places like prefects' bathrooms might be protected the same 
way from being used by the wrong people (of course, a good lock that 
is protected against magical tampering might help, too :-))