The Plutonium in Hierapolis, Pamukkale, is an ancient sanctuary associated with Pluto, the god of the underworld. Dating back to the 3rd century BC, this mystical cave emitted toxic gases, which ancient priests used to demonstrate their “divine powers,” as only they could approach the deadly entrance unharmed. The site features a small stone chamber near the Apollo Temple, marking its religious and cultural significance. Today, the Plutonium offers a fascinating look into ancient rituals, spiritual beliefs, and the natural geological phenomena of the area.