Pokémon Diamond and Pearl/Solaceon Ruins

Just to the east of Solaceon Town are the ruins. The ruins contain the infamous. There are 26 types of Unown that can be caught in the main section of the ruins- each takes the form of a letter A-Z. After catching all 26 types of Unown, talk to the Digging Manic in the Maniac Tunnel near route 214. After you have caught all 26 kinds, a hole will open up at the far end of the Maniac Tunnel. The hole leads to a special room in the Solaceon Ruins where Unown-! and Unown-? are able to be caught. There is a different type of Unown to every room in the ruins. You should be able to catch every one with a quick ball first time round.

Each Unown signifies a letter in the English alphabet. Each of the hallways contains an Unown corresponding to 1 of the letters in "F-R-I-E-N-D". All the other Unown letters can be found in the dead ends found in the hallways.