Luthor's Lair No. 5
From superman.nu: Supermanica
The abandoned coal mine—situated not far from Metropolis Prison—that serves as Lex Luthor's hideout and base of operations during July 1964. Deliberately established by Luthor within easy reach of the prison so that he could escape to it quickly in the event he ever broke out. Luthor's Lair No. 5 is shielded against Superman's penetrating X-ray vision by the deposits of lead ore in the mine's coal-bearing rock (S No. 170/2: pts. I-II—"If Lex Luthor Were Superman's Father!"; "The Wedding of Lara and Luthor!").