The Paris Catacombs
Paris Catacombs are undoubtedly one of the most interesting places on earth. Not so much with the purpose get inside as with historical interest. IN 300 kilometers of salable, halls and crypts are the remains of three million people – inhabitants of Paris by 15 generations. In this city, in fact, the whole system of historical underground are incredibly broad and interrelated. At different levels subway intersects with catacombs, underground rivers, collectors, and other communications.
Russian Secrets
One more secret object in Moscow. Many people have heard about the LHC (the Large Hadron Collider) where was discovered the Higgs boson.
Something similar was being constructed not far from the Protvino town. Here, at a depth of 60 meters is a ring-tunnel of accelerator-storage complexа(ASC), 21 kilometers long.