Concealed Ruins (Japanese: かくされたいせき Concealed Ruins) is a dungeon in Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness. It is unlocked after defeating Regigigas in Aegis Cave. When the player exits Aegis Cave with Team Charm a new entrance to the treasure opens, Concealed Ruins. It consists of 30 floors.
Raikou can be found on B20F, but the player needs to have the Mystery Part or Secret Slab in the bag. There is a locked door on B29F with a possibility of a box containing either Rock Sash, Steel Sash, Ice Sash, or Ancient Ring. At the end of the dungeon, there are six Deluxe Boxes and a Warp Tile leading out of the dungeon.
Wonder Tiles are not encountered in this dungeon.