Mt. Moon is a mountain in Kanto that mostly consists of Clefairy in the central attention of the cave. Despite them being Mt. Moon in Pokémon Firered/Leafgreen
based on the cave, they are the rarest Pokémon you find there. There are no items here in Gold, Silver, or Crystal. There is a square here in Pokemon HeartGold and Soulsilver that sells items in the morning and afternoon.