One of the surprise tourist sites we visited in France was the grottos (caves).
While I was very happy looking around les châteaux et les musee, in the interests of entertaining and possibly educating the children we tried to include a range of other attractions, including the Caves of Lascaux , the Catacombes in Paris and the Standing Stones of Carnac.
Along the same lines, we also visited a number of grottos.
Mostly the grottos seemed to have been discovered by accident when they were half filled with silt, and dug out. Often they were on the side of cliffs of ancient floodplains.
The most surprising thing was a number of them had remarkably fast build-up of limestone into stalagmites and stalactites – sometimes as much as a centimetre per year – and the cave owners had found a way of putting this rapid calcification to profitable use.
In the base of the caves, situated under waterfalls and in pools, were a variety of tourist paraphernalia – ceramic statues, fake flowers, and rubber moulds. Over the course of a six-month period these would calcify, providing a steady stream (pardon the pun) of stone objet for sale as souvenirs. The rubber moulds fill with stone and when the mould is peeled off, they produce plaques that have amazing detail – looking as if they have been cast in ceramic or carved from stone. (A photograph of one such plaque is below)
Now in Australia, the calcification process takes decades if not centuries – this process is unheard of and unviable. But the steady production of products in French grottos seems to have no ill effect on the natural wonders, with the exception of perhaps delaying the build up of calcium on the floor of the grotto. The products are piled up and require regular turning to ensure they don’t calcify together into a mass.