MAPS OF THE UNDERGROUND QUARRIES OF PARIS.
MAPS OF THE UNDERGROUND QUARRIES OF PARIS. Here is a website with maps of the underground quarries of Paris from the year 1200 on. “Quarries being exploited (gypsum and limestone) are colored in orange, and the abandonned [sic] quarries are colored in dark orange.” Notice how much of the area south of the Seine (the Left Bank) is colored in dark orange by the 18th and 19th century. The website also has good explanations of the techniques that engineers have used to support the ground above the quarries.
“Tread softly, for you are treading on my quarries.”