We visited the Clamouse cave while we were on vacation. The tour -- which is only supposed to last 50 minutes -- starts with a movie. Clamouse is a limestone cave which means that water dissolved the rock, left the caverns, and created the stalactite/stalagmite formations. Some cavers are extremists and don't think anyone should be allowed in caves. Even the body humidity coming off visitors changes the natural balance in caves and thus alters the formation of the limestone features. Those cavers find new caves and don't tell anyone about them. (They also probably wear aluminum foil hats when they go outside.) The folks at Clamouse weren't those type of cavers. They were the type of cavers that thought: how many people can we get down there at 8.50 euro per person (6.50 euro for children and seniors)? In places, existing stalagmites had to be chipped away to make room for the concrete walkway. Our tourguide stopped at each of the seven major caverns and lectured us for a LONG time in French about something. It might have been how the cave was formed or perhaps how this particular cavern was discovered or perhaps how he was locked in a closet as a child and how this cavern reminded him of his youth eating Nutella sandwiches that his mother slid under the door. It's not entirely clear except that he had a lot to say. There were a LOT of children in the tour group, too, who would stop suddenly (at knee level) or snap random flash pictures (of my retina apparently) or otherwise just make a nuisance of themselves. I would have gladly dropped a few down a sinkhole if one had been readily available. By the end of the 2 hour long tour I would have paid money to get out.