From Bulbapedia, the community-driven Pokémon encyclopedia.
Lucario Kingdom (Japanese: ルカリオの王国 Lucario Kingdom) is an anime-exclusive location in Sinnoh. It first appeared in Pokémon Ranger and the Kidnapped Riolu! (Part 1), where it is mentioned that the Aura Sphere Riolu hails from it using its powers as the guardian. It may be located somewhere in between Mt. Coronet and Veilstone City.
Pokémon seen in Lucario Kingdom