In the Herault river canyon, under these hills, 25 minutes from the house, stretch miles of caverns. It had poured the day before. When it rains, something like 30 square miles of leaking terrain spill into the caverns. But of course, as the guide emphasized, without rain, there are no caverns. And these are spectacular. And built oh so slowly in human time: a single drop can take two years to fall off the tip of a stalactite. Good bathrooms, too: always important for visitors.