We had enough time between guests for a quick trip to the Auvergne, a part of France focused on the Massif Centrale and famous for its volcanic landscape and mineral water (not forgetting the lentils, A.O.C, naturally).
We had heard about Vulcania, the exhibition/museum/theme park about volcanoes, so that was the first stopping point as an orientation excercise, and the nearby Puy du Dôme is the highest point in the volcanic system, so that was the second. There's not much point in my telling you what Vulcania is; they have a website here that explains things quite well, and in English too. I can give you my impression of the place though, which is that I was underwhelmed. We both were. Not much whelming going on at all.
Perhaps the fundamental problem is that there isn't actually any real volcanic activity going on that you can see, and no amount of translucent plastic with red lights shining through it can disguise this fact. Sure it's possible to make a museum, and to show real layers of now-cold lava flow, and to have rides that evoke some aspects of the experience of volcanoes, but none of it, none at all, is happening, volcanic action.
So you have a combination theme park, museum and exhibition about volcanoes. The theme park rides were of the "moving platform" type that shake you about while you watch a film. They spray you a bit in the wet bits and one had infra-red lamps so you feel hot when looking at molten lava. And the 3-D dragons were cute, but not much to do with volcanoes.
There was a fountain that they call the geyser, that by pushing buttons you can make do different things to illustrate geyser-type activity, but at the end of the day, it's a fountain.
The VulcanBul is an autonomous car, illustrating the "car of the future". Battery-powered, driver-less, and steered automatically by GPS, it is covered in what I think is perspex so you get a clear view of the outside. It goes at about 3 MPH, and a commentator, who could also be driving if it was drivable, tells you what it is you're looking at. But according to the description, it doesn't run in bad weather, which seems to me to be the time when one would most appreciate a ride outside and under cover. I don't know if this is because the technology doesn't work in the rain, or if it's because of some management policy, but it struck me that they'd have been better off with a horse-drawn buggy. Probably more representative of the car of the future, too.
We were told to allow a whole day for the visit, which is probably necessary in high season if you want to do all the rides, because there were Disney-esque queuing systems in place for use in times of high demand, that will delay your appreciation of the site.
Verdict: Only if your kids are into geology or volcanoes, or it's raining and they're getting fractious (and they don't want to go on the VolcanBul).