NieR: Automata's 3C3C1D119440927 DLC unlocks three challenging Colosseums. After receiving the Mysterious Letter, you'll need to locate these arenas to earn unique rewards. Each Colosseum features six ranks of progressively difficult enemies.
Colosseum Locations in NieR: Automata
Trial of the Sand Colosseum
Located in the desert. From the "Desert: Center" access point, look to the right (facing the desert entrance) for an orange diamond marking its location. A machine guards the entrance, but it won't pose a significant obstacle. Completing Rank S rewards the Destroyer Outfit (A2).
Gambler's Colosseum
Found in the Flooded City. Begin at the "Flooded City: Coast" access point. Follow the path towards the coast (the same route used to protect the resource ship). At the end, locate a waterfall to the right. Circle around the building to the left, where a Resistance member guards the entrance. Bribe the guard with 1,000 G to enter and start the Gambler's Colosseum quest. Completing Rank S rewards the Revealing Outfit (2B).
Underground Colosseum
9S ONLY: This Colosseum is accessible only while playing as 9S. Start at the "Forest Zone: Center" access point. Follow the left edge of the forest until you reach a group of machines training near a large waterfall. Pass through the waterfall to access the Underground Colosseum. Completing Rank S rewards the Young Man's Outfit (9S).
