How did MWPP make the Maunderer's Map?

[houyhnhnm102]

No: HPFGUIDX 154186

--- In HPforGrownups at yahoogroups.com, "Hagrid" <aussie_lol at ...> wrote:
>
> The Map has blind spots where it can't see anyone. So how come some 
> areas show up and not others?
> 
> The three areas not shown on the map I know of are:-
> 
> - Hagrid's Hut (or Lupin would have seen Pettigrew there - POA)
> - Room of Requirements (where Draco disappeared off the map - HBP)
> - The Chamber of Secrets has never been mentioned again.
> 
> Do the makers of the map have to have been in those areas of Hogwarts 
> to be able to include them on the map? 

houyhnhnm:

Oh, I like this.  I had assumed the RoR was simply unplottable for 
magical reasons, but the fact that Lupin could not see inside Hagrid's 
hut has been nagging at the back of my mind.  I hadn't really looked at 
the missing spaces altogether before.

No one knew the location of the Chamber (except for Riddle) so it is 
not surprising that it was not on the Map.

Maybe they did have to actually be in an area to put it on their map.  
A rat would have been an ideal form in which to sneak around the 
castle.

Why doesn't the Shrieking Shack show up on the Map though?  Or anywhere 
else outside of the Hogwarts grounds.  How much of Hogwarts' ancient 
magic is incorporated into the Map.  Did the Marauders really know what 
they were messing with?

I was really convinced by the argument at LiveJournal (referenced by 
Marion) that the Map is a Dark object.