I'm standing on a sidewalk in the early morning. The great avenues of Paris are silent, and the shops are closed. From a bakery comes the smell of fresh bread. Suddenly, a man with long hair and a lamp on his head appears from a hole in the sidewalk. He is soon followed by a young woman holding a lantern. Mud covers their boots. The man places the iron cover over the hole and takes the woman's hand. Together, they run down the street, smiling.The couple had been exploring the tunnels beneath the city.When the Romans occupied Paris, they cut out stone from deep within the earth to build their city and make sculptures. Later, the French used more stone to construct the Notre Dame Cathedral,the Louvre, and many other buildings. This left huge underground tunnels upon which part of the city now stands. Once used for growing mushrooms.burying the dead,or as hiding places during wartime,today they are mostly forgetting,except by "cataphiles"-people who love to go down into the tunnels below Paris,even though it's actually not permitted.