DavidWilliams wrote:
Anyway, please realise that I am *not* asserting that there is no ruined castle at La Vialasse, only that it's odd that the IGN have failed to notice it.
No, I agree. It is strange, given that, as you point out, the most vestigal of remains, do qualify for inclusion. The 1:25,000 map is littered with such examples. There'll probably now be some hare-brained conspiracy theory that the IGN have deliberately omitted it! (Remember the one about changing the height of Cardou!)
One thought does occur. Recalling the passage in the Lamy book about Jules Verne that prompted this thread in the first place, the reference is to something that has the shape of a boat - pointing towards Bugarach. Reading back through a pm someone kindly sent confirming the location, it would appear, if my understanding is correct, that the hamlet itself forms this shape, the discernibility of which is best demonstrated when looking down on it from above; from the D14, close to the turn-off to the back road to Rennes-le-Chateau.
Anyway, I wonder, therefore if the castle is now more of an earthwork, rather than bits of stonework, if you get my drift. In other words, if we're talking about some form of sculpted landscape mound, the terracing of which may reflect the buried foundations of a castle, upon which a hamlet has subsequently been built - adopting the outline of the former castle, whilst obliterating its existence.
Maybe that's why no indication on the map. Perhaps you need to be able to see it, for it to qualify, and that's why the other ruins referred to on the hill above do get shown, but this, possibly more significant structure in its time, does not.
Obviously none of the above speculation is a substitute for actually going to look at it for oneself, which I'll certainly do, in order to sate my curiosity, but that won't be for a few more months. In the meantime, Colin Boucher mentioned some photos on his posting, which would be fascinating to see.