You're you. You have your two hands and two feet and a camera. That's it. Can you climb up a freaking skyscraper without any protective gear, safety net, rope, and whatever else sane people use when they climb? This guy did.
Bunker-42 was built during the Cold War and was a classified bunker equipped with everything necessary in case of a nuclear attack. After the end of the Cold War, it's been transformed into Russia's Cold War Museum.