catacombs of paris
cave
gallery
hôpital du val-de-grâce
salle Z
trespassing
underground quarry
val-de-grace
vaults
Salle Z under the Val-de-Grâce Hospital
Catacombs of Paris (off-limit area), about 20 meters (60 feet) underground, under Paris city center.
This is a part of the 200 Km network of ancient tunnels not opened to the public, but regularly visited by trespassing urban cavers called "cataphiles". See more information in the description of the photo album.