Location from Solo Leveling by Chugong
The impossible dungeon that changed everything — a hidden S-Rank gate disguised as a D-Rank, containing the Cartenon Temple where the Shadow Monarch's System chose Sung Jinwoo.
The Double Dungeon is where Solo Leveling truly begins. What appeared to be a routine D-Rank gate contained a second, hidden dungeon of incomprehensible danger. Jinwoo's raid party discovered it and entered, finding the Cartenon Temple — a vast stone chamber filled with statues of warriors, a throne, and a set of commandments carved into the walls. When the party violated the commandments, the statues came alive and slaughtered nearly everyone. Jinwoo survived — barely — by solving the temple's final test. In his dying moments, a message appeared: 'You have been chosen.' The System activated. A game-like interface materialized in his vision. The weakest hunter in the world received a power that would make him the strongest being in existence. The Double Dungeon was not a natural gate. It was designed by Ashborn, the Shadow Monarch, as a test to find a worthy vessel. The entire dungeon — the statues, the commandments, the death trap — was an audition. Jinwoo passed.
Also known as: The Double Dungeon, Double Dungeon, The Impossible Dungeon