PARIS — There are two kinds of gruyere in France: the literal one, an odorous, holey family of cheeses produced near the Swiss border; and the figurative one, the gruyere parisien, equally as earthy, porous, and complex. It refers to the tangle, deep under the city’s streets, of metro and train lines, sewers, and ancient quarries that extend much farther and are much more active than most Parisians realize.
The quarries have lived many lives. Originally providing limestone that remains the basis for the city’s classic streetscapes, they housed mushroom farms once rock extraction was halted. Sections of the mines not used for champignons de Paris were taken for a very different purpose. Because of the city’s exploding population, mass graves were overflowing, causing putrid odors and spreading deadly infections. From 1786 through 1814, the city emptied its graves and transferred bones into the quarries, including those of Robespierre and Rabelais, some of France’s most important historic figures whose skeletons remain anonymous among the others underground. Now a municipal museum called the Catacombs of Paris, the ossuary is the world’s biggest necropolis and one of the city’s most popular tourist attractions.