Mythic Brittany?


I'm looking for information about Mythic Brittany, beyond what can be found via Google or in the Faerie Stories book. Specifically, I'm looking to set a saga in what are today the Morbihan and Finistère communes, in the neighborhood of Quimper and Brest.

In case it helps focus the kind of information I'm most interested in, the idea that the proto-troupe is favoring is to put the covenant in a regio whose borders lie offshore, west of the mainland and some ways north of Belle-Ile-en-Mer. Current thinking is that the base level of the regio would consist of a stretch of sea known, and avoided, for reefs, treacherous currents, sudden storms, and stories of the ghosts of those who've perished trying to cross it. Following particular course into the regio would bring one to the next level, consisting of a wave-lashed island with but one navigable harbor, surrounded by cliffs that vanish up into a dense, perpetual mist. The third level of the regio would be reached by some pathway from the harbor up the cliffs and into the mist: the mist recedes somewhat as one crests the path, revealing below a wooded island interior dotted by stone menhirs.

you can read the journals of our Saga (set in Brittany)

you could do the same as I did and get the Michelin Green Guide to Brittany, as it's full of asides and references to small but interesting places, and to local legends.
you can try to get hold fo the French NGS maps, which have excellent scale, and show contours and small details. (You have to mentally edit, removing many habitations and modern roads, and reinstate ancient forest etc - but hey - the topography is there.
You'll also find that the region is chock full of ancient stones!

You can also search the Web for Brittany related things, but you have to wade through reams of holiday lets and house sales, and other twaddle - rather tiresome - but there are gems out there.