Building the world’s largest polar-aligned telescope is no simple or small task. This concrete bunker is the control building and base pedestal for the 140-foot (43-meter) telescope in Green Bank, West Virginia. The reinforced concrete base uses 140 tons of steel inside 5700 tons of 5000-psi concrete. It was built on the bedrock 30 feet below the surface in order to keep the 8200-ton telescope from falling over. The telescope’s control room, offices, and hydraulic pumps were housed inside the 3-foot thick walls of this monstrous building.