Ensemble de grottes à concrétions Sud de la France

On the way towards the Mont Perdu WHS from the french side, I made a visit to the "Gouffre D'Esparros" cave, which is part of the obscure TWHS "Ensemble de grottes a concretions du Sud de la France". The cave is a bit in the middle of nowhere. However, the GPS should find it, the roads are fine and the infrastructure for the visit is actually pretty good. Despite visiting on a long weekend with nice weather, I was the only visitor for the early tour, so I had my own private tour guide. The cave itself is quite nice (but I have a soft side for caves). Although the cave has a rather vertical layout, the tour path itself was completely horizontal and easy to walk. The stalagmites were nice but not too numerous. The highlight of the cave is the finely preserved frostwork - a crystal-like outgrowth that covers many walls and rocks. A downside of the visit was that photography is totally forbidden for non-obvious reasons.
So, while the visit itself was quite nice and by all means recommendable, the nomination as a TWHS is in a poor state. The caves seem to be put together without any clear reason or idea. There is practically no description or justification given at the UNESCO site. And caves are quite common in the world - almost every country has a few, and quite a lot are already WHS sites. So it is completely unclear what is so special about …