Metatron has built a really cool place with wonderful details in Cloud Party, the Metro 2033 (Dmitry Glukhovsky) VDNKh station. You can visit it here: https://a.cloudparty.com/went/SdZsrimHr Background story:
"In 2013, a nuclear war occurred, forcing a large amount of Moscow's surviving population to relocate to underground metro stations in search of refuge from the outside world. Eventually, those who settled in the underground train stations evolved their homes into independent station-countries. Soon, new factions grew, starting with new Soviet Union (whose members were strong Marx idealists) and the Fourth Reich (orneo-Nazis)".
"As these small states began to evolve, the New Soviet Union and the Fourth Reich entered war, as both sought to control the metro and its resources. As the war raged, those stations who refused to join either side were massacred by the militants, raided by bandits, or outright destroyed by the Dark Ones - paranormal, otherworldly, mutated humans and animals who live in the nuclear-ravaged surface world. In one of these stations is where the events of Metro 2033 unfold." Read on: http://en.wikipedia.org/wiki/Metro_2033_(novel)