Solaceon Ruins

1 Pokémon can be caught at Solaceon Ruins in Sinnoh — highlighted on the map below.

East of Solaceon Town lie the Solaceon Ruins, the Sinnoh dwelling place of the Unown; in the Hisui era the site was charted as part of the Crimson Mirelands. Catching an Unown and presenting it to a boy in town unlocks the Seal matching that Unown's letter.