Lake Verity/Manga

Pokémon Adventures
When he was little, got lost by the lake while trying to find a Red Gyarados with. He suddenly noticed a mysterious glow over the lake and passed out, later to be found by Pearl and his father, Palmer.

After Diamond, Pearl and decide to split up in order to stop Team Galactic, Diamond heads towards Lake Verity, where Team Galactic captures Mesprit in Mixing It Up with Machamp.

Pokémon Diamond and Pearl Adventure!
Lake Verity was first visited in In Search of the Legendary Pokémon Dialga!! while Mitsumi was on her bike.

In Team Galactic's Ultimate Warrior, Cyrus and Team Galactic went there to take, completing the collection of the Lake guardians, and then went to their headquarters.