Mount Yamantau

Yamantau (, ) is a mountain in the Ural Mountains, located in Beloretsky District, Bashkortostan, Russia. Standing at 1,640 metres (5,381 ft) it is the highest mountain in the Southern Ural section, and is featured within the South Ural Nature Reserve. 
Yamantau is notable as the subject of claims by the United States that a secret extensive bunker complex of the Russian government or Russian Armed Forces is contained within the mountain, similar to the Cheyenne Mountain Complex.
Name.
The name of the mountain is derived from "Yaman Tau" (Яман тау), which translates to "evil mountain", "bad mountain", or "wicked mountain" in the local Bashkir language and the other Turkic languages of the Idel-Ural region such as Tatar and Mishar Tatar.
Bunker complex claims.
Yamantau, along with Kosvinsky Mountain (600 km to the north), are claimed by the United States of being home to a large secret nuclear facility or bunker, or both. Large excavation projects have been observed by U.S. satellite imagery after the fall of the Soviet Union, as recently as the late 1990s during the government of Boris Yeltsin. During the Soviet era two military garrisons, Beloretsk-15 and Beloretsk-16, and possibly a third, Alkino-2, were built on the site. These garrisons were unified into the closed town of Mezhgorye () in 1995, and the garrisons are said to house 30,000 workers each, served by large rail lines. 
Repeated U.S. questions have yielded several different responses from the Russian government regarding Yamantau, including it is a mining site, a repository for Russian treasures, a food storage area, and a bunker for leaders in case of nuclear war. Responding to questions regarding Yamantau in 1996, Russia's Defense Ministry stated: "The practice does not exist in the Defense Ministry of Russia of informing foreign mass media about facilities, whatever they are, that are under construction in the interests of strengthening the security of Russia." In 1997, a United States Congressional finding, related to the country's National Defense Authorization Act for 1998, stated that the Russian Federation kept up a "deception and denial policy" about the mountain complex after U.S. officials had given Cheyenne Mountain Complex tours to Russian diplomats, which the finding stated "... does not appear to be consistent with the lowering of strategic threats, openness, and cooperation that is the basis of the post-Cold War strategic partnership between the United States and Russia."
Popular culture.
Yamantau is the subject of a level in the 2010 video game "" where Hudson and Weaver eliminated the complex, returns in Call of Duty: Black Ops Cold War (2020) as where the missing nuke is, and is an important plot point in the 2019 video game "Metro Exodus".
The mountain is also featured on the introductory animation for | Season 3 Battle Pass, where the plot of the video is set on an enemy base in the slopes of the mountain, in 1984, during the now dissolved Soviet Union.