Testing Ground 12 in Atomic Heart presents players with one of the most intense endgame challenges in the facility. Situated across the bridge near the hospital grounds, this hidden testing ground blends complex electromagnetic puzzles with demanding combat encounters. Completing this dungeon yields crucial weapon upgrades that significantly boost your late-game arsenal.

How to Access Testing Ground 12

To reach Testing Ground 12, players must progress past the Theater section and cross the bridge into the hospital area. Follow the shoreline path down toward the beach where a secluded cave opening leads into the cliffside. Navigating through the cave system reveals the elevator that descends into the underground testing complex.

Solving the First Magnetic Platform Puzzle

Upon entering the facility, players encounter a large chamber featuring magnetic ceiling coils and adjustable platforms. Rotating the valve mechanisms adjusts the platform heights, allowing you to create a traversable path across the room. Applying the Shok ability to the ceiling magnets alters the polarities to raise or lower the platforms safely.

Surviving the Middle Combat Arena

Unlike most other testing grounds, Polygon 12 features a major boss encounter right in the middle of the trial. Players must face an NA-T256 Natasha robot accompanied by supportive LUC-1 Owl flying drones. Utilizing explosive weaponry like the Fat Boy while dodging airborne rockets is essential for surviving this battle.

Final Puzzle Room and Reward Chests

The final section requires manipulating candles and sliding magnetic shutters to open the exit pathway. Solving this room unlocks access to the ultimate chest containing valuable weapon modules. Players who conquer the facility will claim top-tier upgrades including the KS-23 Thermal Scope, Kalash Electrokinetic Stock, and Pashtet Reflex Blade.