In Metal Gear Solid 3: Snake Eater, Snake confronts Volgin at the fortress of Groznyj Grad.
Groznyj Grad is a major Soviet military complex in the game’s fictionalized 1964 setting. Naked Snake infiltrates the fortress during Operation Snake Eater, gathering intelligence and attempting to rescue scientist Nikolai Sokolov. The location contains laboratories, barracks, weapons facilities, and the hangar associated with the Shagohod project.
The fortress is also the setting for several major story events. Snake battles Ocelot there, rescues Sokolov, and eventually fights Colonel Volgin. The climactic confrontation leads into the Shagohod chase and the escape from the Soviet facility.
Groznyj Grad is sometimes confused with other locations in the game, such as Rassvet, where Snake first meets Sokolov, or Tselinoyarsk, the broader region in which the mission occurs. The fortress itself is specifically named Groznyj Grad, a Russian phrase meaning “terrible city.”