Avenue d'Orléans
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 album description.
The lead pipes contained thousand of telephone lines, but now they use optic fiber links, so those pipes have been removed.