Showdown Mountain (Japanese: 決戦ヶ岳 Showdown Mountain) is a dungeon in Pokémon Super Mystery Dungeon that is located on the Water Continent. After flyers in Lively Town state that Entei will be turned to stone at Showdown Mountain, the player and their partner travel to the dungeon with the Expedition Society in Chapter 15.
At the end of the dungeon, the team finds Entei turned to stone. They then discover Krookodile nearby, who drops a stone tablet as he flees. As a result, the Expedition Society begins to suspect that Krookodile might be behind the incident.