After beating Stormy Sea, you should receive mail about the Buried Relic. Go to Pokémon square and talk to Lombre then Shiftry to unlock this massive dungeon. If you already beat Stormy Sea, but did not get Buried Relic, empty out your mailbox COMPLETELY, and then go through Tiny Woods.
Note: do not enter the dungeon until you buy the friend area Final Island. It is Mews Friend Area.
The Dungeon
Warning: This dungeon requires a quicksave before entry, so don't take anything important with you.
The first fourteen floors shouldn't be too hard. You'll face Regirock on the 15th, Regice on the 25th, and Registeel on the 35th. Each will drop a part. When you have all three parts, they will fuse to become a music box. From floor 36-98, there is a slight chance of encountering Mew as long as you possess the music box. Do not try to use it; if you do the music box will break! You can recruit Mew if you have the Final Island friend area. Shedinja, the one that is really hard to kill, appears on floors 26-39 (Floor 35 only contains the boss Registeel and have no Shedinja) and try to prepare or get some gravelerock to kill them or use moves that are super effective like fire moves and flying moves and so on. There are only Golem on floor 99.
There is a chance of finding buried items and Monster Houses on any floor. Run through corridors and rooms and if you stop in the middle, use the move Rock Smash or use a Ghost Pokemon OR have the IQ Skills called Super Mobile (The highest IQ Skills you can get) to beak the adjacent walls (All around you, including walls that are diagonal to you) to get items. The best thing you can get is Joy Seed and other great stuffs like Protein, Iron, Calcium, Zinc and Ginseng. The worst probably item may just be common TMs or money. There is only ONE hidden item on each floor. Note: Some are hidden way-off the room or walkway, hidden deep in the sea of walls. Rock Smash may not help IF you want every single items on the floor. Super Mobile may be the best way to get those hidden items. But BEWARE!, ghost Pokemon like Gastley and Haunter and other Pokemon that are able to walk or fly through walls (like Shedinja)can also pick up these items, and once they get the hidden items that are Protein, Iron, Calcium and Zinc, THEY WILL DRINK IT!!! So sorry, no Protein, Iron, Calcium, or Zinc for you! Ginseng is spared though. (NOTE: Walkway junctions OR room entrances may cause you to stop. There MAY or MAY NOT be any items there, depending if there is. Walkway bends do not stop you.)
Mew is tricky to find, since there is a low chance of it appearing on each floor, and there is only one chance per floor of it appearing. It is very much possible that you won't even find Mew at all through the WHOLE dungeon.
Items
Special Items
- HM Rock Smash on floor 45 if you have a key
- HM Strength on floor 60 if you have a ghost Pokémon or a Pokémon that knows rock smash or a mobile scarf or mobile orbs
- HM Flash on floor 70 if you have a key
- HM Cut on floor 80 if you have a key and a ghost Pokémon or a Pokémon that knows rock smash or a mobile scarf or mobile orbs
- Rock Part Gained by defeating Regirock
- Ice Part Gained by defeating Regice
- Steel Part Gained by defeating Registeel
- Music Box Once all 3 parts are collected they will become this
WARNING: If you befriend Mew, some chances are that you can't get these items, so if you want the items come back to the dungeon without fainting
Enemies
Out of every Pokémon in the game, Mew is the trickiest to get. Always look at your comment box for: Mew Transformed into _______ or Mew used Transform. If you befriend Mew, you will be instantly teleported out of the dungeon. With a friend bow and a Pokémon over level 55 it can be easily recruited. It is one of the best Pokémon for level 1 dungeons.