Someone should have a Google Earth sort of map of all of the underground sites like Derinkuyu, Cappadocia, Turkey; Kaymakli, Cappadocia, Turkey; Beijing Underground City (Dixia Cheng), Beijing, China; SubTropolis, Kansas City, USA; Naours, France; Orvieto, Italy; The Louisville Mega Cavern, Louisville, Kentucky, USA; RESO (The Underground City), Montreal, Canada; Cheyanne Mountain Complex, Colorado, USA; Raven Rock Mountain Complex (Site R), Pennsylvania, USA; Bunker-42 (Tagansky Protected Command Point), Moscow, Russia; Mount Weather Emergency Operations Center, Virginia, USA; Wieliczka Salt Mine, Poland; Petra, Jordan; Catacombs of Paris, France; Odessa Catacombs, Odessa, Ukraine; Caltech Steam Tunnels, California, USA and all the other steam tunnel systems under campuses; Disney Utilidor System, Florida, USA; Gotthard Base Tunnel, Switzerland; Chiashan Air Force Base, Taiwan; Iranian Underground Missile Bases, Iran; Željava Air Base, Croatia/Bosnia and Herzegovina; Minot Air Force Base, North Dakota, USA; York Cold War Bunker, England; Bundesbank Bunker Cochem, Germany; Svalbard Global Seed Vault, Norway; Ronald Reagan Minuteman Missile State Historic Site, North Dakota, USA; Underground Project 131, China; Ark D-0 / Tito's Nuclear Bunker, Bosnia and Herzegovina; Bunk'art, Tirana, Albania; Greenbrier Bunker (Project Greek Island), West Virginia, USA; Tirpitz Bunker, Denmark; Camp Century (Project Iceworm), Greenland; Los Angeles Tunnels, California, USA; Guanajuato Tunnels, Mexico; Moffat Tunnel, Colorado, USA; The Channel Tunnel (Chunnel), United Kingdom/France; Chicago Tunnel Company Freight Tunnels, Illinois, USA; China Jinping Underground Laboratory, China; Sanford Underground Research Facility (Homestake Mine), South Dakota, USA; Sudbury Neutrino Observatory (SNO), Canada; Gran Sasso National Laboratory (LNGS), Italy; Onkalo Spent Nuclear Fuel Repository, Finland; Hill Country Wine Cave, Texas Hill Country, USA; ALMA Sports Hall, San Pedro de Atacama, Chile; The Inside Home, Ammaneh, Iran; Deep Time Palace, Chang Chun, China; Sancaklar Mosque, Istanbul, Turkey; Villa Aa, Aarhus, Denmark; Hacienda de la Paz (LA Mansion), Los Angeles, USA.
