US displayed its nuclear power in World War II forcing USSR to build a secret city that stayed off the maps for decades!

Krasnoyarsk-26

Another name given to this region is “Krasnoyarsk-26.” The place remained a mystery for Soviet people until “Glasnost” era began in the latter half of the 1980s. Thanks to the “Glasnost era” that focussed on transparency the secret finally came out in the public domain. Surprisingly, before that, the region had no trace even on official maps.