Share this on Facebook
download .zip with all pictures
Probably not very old, but it’s hard to tell. Somewhere between 10 and 50 years for some of them. The ones on the first picture are actually quite healthy so I would say no more than a few years, but in the second spot some of them were starting to look quite bad.
The date on the pillar is unrelated, but these places have been exploited during the XVIIIth and XIXth century for limestone (exactly like the currently so-called catacombs of Paris), then used for growing mushrooms. Sometimes what you find on the walls is just pure graffiti.