How do you get to the top cliff of the solaceon ruins?

Question

When you're about to walk into the ruins there is a cliff above you that had an item on it. How do you get there?

Answer 1

You have to catch Every single Unown (letter wise) possible, from A-Z. Then, talk to the man on Route 214 that is digging that tunnel. He will have completed it by the time you catch all the Unown's, and you will be able to reach that cave.

Just for the fact to have a source...

The room above the rest of the ruins, only accessible after the Ruin Maniac has finished digging the Maniac Tunnel through from Route 214 (which occurs after obtaining one of each alphabetic Unown)