The kid from the ruins will be there and if you speak to him after capturing all the Unowns, you get a Seals. Jump down the third ledge (not the fourth one) instead to find a house. Go back to Solcean town and locate the same ruins. They only know hidden power, so they can't do much damage to your Pokemon. Find him and talk to him so he will leave. There will be 4 ledges within jump down the fourth one and you'll enter another ruin. Near the exit at the top on your right there is a hidden opening go inside!