Chapelle St Marc, a couple of km SE of Malestroit
I've been unable to find out any info about this church/chapel - which really surprises me. It's bang next to a Roman Road (which in itself is a rarity here) and it's on one of the Compostella pilgrimage sites, so it should be documented somewhere on t' internet. I expect I'll discover something sometime (and if I do, I'll retro-edit this post - or I'll post another image later, when the sun's out...).