Mushroom house

So this house is up by Beynac castle. The roof is one of those they call "lauze" or something like that, and you usually see them only on dovecotes, or bories. They are flattish rocks, laid out around the roof. I don't think there's any mortar anywhere involved in them. P said this is not a house; it's a mushroom. It's the only house I've ever seen with one of these roofs.