It's an old irony: we often destroy what we enjoy most. Take the Lascaux Cave, the site of 17,000-year-old Stone Age paintings, a place sometimes called the "Sistine Chapel of Prehistory." Over time, so many visitors entered to admire it that their exhalations caused mould to grow on the walls, damaging the paintings.
The cave was closed down in 1963, thereafter off-limits to the public and accessible only occasionally to visiting scholars.
A partial replica, Lascaux II, was built at the same site in Montignac in Dordogne province, with facsimile paintings of the Paleolithic originals. Now more than 30 years old, this site too has suffered the same kind of damage as the real thing and has needed refurbishment.
Enter Lascaux IV: This ambitious project is a reconstruction of the original cave at a cost of about 60 million euros ($99.6 million). For the first time the entire grotto with its more than 1900 animal paintings is being reproduced.
This is a huge undertaking. The figures painted by the Cro-Magnon humans using natural pigments and the engraved rock images were of astonishing quality and precision, and the same effort is needed for the reproductions.