I saw one like that but more earthbound on a high hillside over looking the Lot. Though that still had a lot of the covering mound. I have a list of local ones to where my dad lives, but sadly no gazateer of the best ones to see in the wider area.

If you are in that area go to Pech Merle, absolutely blew me away. That doesn't happen quite so often these days!
http://www.quercy.net/pechmerle/english/visite.html