A secret metro line that officially does not exist — Moscow's most durable urban legend. As the story goes, "D-6" links the Kremlin with bunkers, the ministry building on Smolenskaya and Stalin's Near Dacha, and an entrance sits in the basements of Moscow State University's main building, which is said to have as many floors below ground as above. Diggers have published maps for decades that do not agree with one another; the defence ministry has never confirmed anything and never clearly denied it either. The legend runs on that silence: the less that is said, the more detailed the map becomes.