Buried Relic
Buried Relic is a dungeon in Pokémon Mystery Dungeon. It contains 99 floors and is the location of Mew. There is a compulsary save upon entry.
It is possible to visit Buried Relic after the first completion of Stormy Sea. After receiving a letter about it and talking to Lombre, Shiftry will grant access to the dungeon.
Floors 15, 25 and 35 are a fight with each of the legendary golems, Regirock, Regice and Registeel. On defeating them, the RockParts, IceParts and SteelParts respectively will be received. Once all three are obtained, they will join together to form the Music Box. When this item is in the bag, Mew can randomly be found from floor 36. However, doing anything with the music box will break it. The player will be automatically teleported out of the dungeon on befriending Mew.
Porygon is exclusive to Red version while Porygon2 is exclusive to Blue version.