In Japan, Pocket Monsters was first released as Pocket Monsters Aka ("Pocket Monsters Red") and Pocket Monsters Midori ("Pocket Monsters Green") while Red and Blue were released in North America and elsewhere. In Japan, Pocket Monsters Ao ("Pocket Monsters Blue"), with improved graphics as opposed to the older first-generation games, was released after the original Aka and Midori. It contained Pokémon that could be found in places not originally in the Aka and Midori versions. An example is that Ditto was added to the Rock Tunnel and Lickitung could be caught in the wild. Also, Unknown Dungeon was totally redesigned, and its layout was used by the Red and Blue versions.