I don't think so. - Edit 1
Before modification by Skeeve the Great at 14/02/2010 04:28:42 PM
Graendal can only compel those who come to her. Seems likely that anyone they tell their story to about a "well known" estate that is suddenly changed hands would raise a few eyebrows.
But even she Compelled only the ones that were coming to her, that disproves the original post theory that it can't be "well known" and "largely forgotten". Because to Compell so many, who apparently knew the place, the place itself should be well known. And after Compelling so many who knew the place it's no surpise the place now is "largely forgotten".
So, to summarise you points:
1) Graendal Compelled only the ones that were coming to her;
2) We, the readers, know that Graendal Compelled a lot;
3) The logic conclusion is that in order to Compel a lot that were coming to you, this lot needs to know the place, thus the place needs to be well known;
4) After Compelling a lot of people, who knew the place, it's logical to conclude that there are many less left who knew the place. It'll be hard to find the people who would share the knowledge of the location with you. Thus, the place become "largely forgotten"
5) Case closed.