The Soviet Union founded quite a few towns during the Cold War that never appeared on maps; secret sites where research was done, bombs were built, or nuclear armaments were made ready. One such "closed city" on the eastern edge of Russia was called Gudym by the locals, but its official designation was Anadyr-1.
Gudym was built in the late 1950s, complete with an underground base for storing nuclear warheads. Over five thousand residents (military and their family) lived there beginning in 1961, residing in buildings above the secret facility that stored three RSD-10 pioneer nuclear missiles, allegedly intended for Alaska, Washington state, California and South Dakota in the event of nuclear war.
The nuclear weapons were removed in 1986, and eventually the town was abandoned. All that's left are the empty facilities, which haven't been updated since the '60s and are now quite run down. See a gallery of images from Gudym as it appears in the 21st century at Messy Messy Chic.
(Image credit: Hardscarf)