This is an interesting article (unlocked) about the Catacombs in Paris and the renovation that is taking place. Some areas that have been closed to the public will now be opened due to the renovation.
Two centuries of visitors brought humidity and carbon dioxide, both of which contributed to falling walls and molding bones. A dilapidated electrical system, almost untouched since 1974, hardly helped.
The restorers’ primary challenge was to ensure that the renovations did not compromise the site’s haunting essence, Ms. Knafou said. “The first priority is, above all, to preserve the site and maintain a balance between the visit and the conservation of the remains,” she added.