Mt. Thunder (ライメイの やま, Mt. Raimei) is a dungeon that appeared in Pokémon Mystery Dungeon: Red Rescue Team and Blue Rescue Team. It is the sixth overall dungeon in the game and the first to feature a Legendary Pokémon boss fight; in this case, being Zapdos. Mt. Thunder is mainly inhabited by Electric Pokémon, but also contains populations of poison and flying Pokémon.
Mt. Thunder is also the first dungeon to feature a save room, which allows player to save their progress whilst inside a dungeon. The save room appears after the player scales the tenth floor and the peak of Mt. Thunder ensues the save room.