How do you get on top of solaceon ruins?

the entrance is the highest point

No, The high tunnel is hard to get to. You need to catch all the letter unowns

then go to the RUin Maniac on Rte. 214 then he has another room to enter (that has ! & ? unowns) then you go out the other hole and wah lah you are on top of the ruins!!! :)