First you go to Veilstone City.Then keep going south.You'll end up at Route 214.You'll see stairs if you go straight slowly.Then you'll see a cave entrance.Go in.You'll see the Ruin Maniac.But, you know how you go to the Solaceon Ruins you see another cave entrance on top of the bottom one?Well if you catch all the unowns(A-Z),you can get up there by going to the Ruin Maniac.You'll see after that it will be the Ruin Maniac tunnel.Oh yeah there are only two ways to make the Maniac Tunnel.Catch all the unowns, or complete the national dex.
The Pokemon Unkown.
You can see one at the Ruin Maniac's cave, which is just south of Veilstone City. You have a 5% rate of meeting it, but don't worry, because the Pokemon that are available there are only Hippopotas, Zubat and Geodude, so the 5% is actually a lot. The rate of meeting Hippopotas increases if you have more Unown, but you can also catch one without any Unowns.
i havn't done it yet but if you catch all the unowns and go to the ruin maniac in ruin maniac cave, he'll most likely give you something nice
Capature All the unkowns. The located on the right of Solocaoen Town.
the purpose of caching the unown is (a) to get all the seals from the little boy in solaceon town and (b) to get the ! and ? unowns (talk to ruin maniac in route something
The ruin maniac is under veilstone city in the cave on the left.
It can be found in Ruin Maniac's Cave or Ruin Maniac's Tunnel by walking.
Ruin Maniac Cave
You can get the TM28 (Dig) on Route 214 in the Ruin Maniac Cave in Pokemon Diamond.
It leads to a room with unknown shaped like this ? and !.
You can find TM Dig at the Ruin Maniac Cave.
The Pokemon Unkown.
well, dig isn't a HM in Pokemon diamond, but it is an TM. anyway, you can find it on route 214, inside a cave where you'll find the ruin maniac- the same place where you find hippopotas.
if you mean the ! and ? unown you can, that's how you get them anyway!
http://www.youtube.com/watch?v=FZ-25C0JskM Watch this it shows you K
get an known for him
Hippopotas has an chance of spawning in the Ruin Maniac cave. The chance of encounter is about 1/20 so it may take awhile.