Coober Pedy, South Australia (??????????) [source:Huanqiu] Wieliczka salt mine, Krakow, Poland (?????????????) [Source:Huanqiu] The Paris Catacombs, France (?????????) [Source:Huanqiu] Cappadocia, Turkey (?????????) [Source:Huanqiu] Mary King's Close, Edinburgh, Scotland (????????????) [Source:Huanqiu] Seattle Underground, Washington, United States (????????????) [Source:Huanqiu] G-Can flood surge tunnels, Tokyo, Japan (?????????) [Source:Huanqiu] Shanghai Tunnels, Portland, Oregon, United States (??????????????) [Source:Huanqiu] Greenbrier Bunker, West Virginia, United States (??????????????????) [Source:Huanqiu] Cu Chi tunnels, Vietnam (???????) [Source:Huanqiu] Moose Jaw, Saskatchewan, Canada (?????????????) [Source:Huanqiu] City of Caves, Nottingham, UK (??????????) [Source:Huanqiu] |