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The Secret Garden (Japanese: 秘密の庭 Secret Garden) is a secret location on the island city of Alto Mare in the Johto region. It is featured in Pokémon Heroes: Latios & Latias.
In the anime
The Secret Garden at dusk
In the film, the Secret Garden is the home of the legendary Pokémon Latias and Latios. It is also home to other wild Pokémon, and of the extremely rare jewel Soul Dew. It is an incredibly large place surrounded by a stone wall, and has many fountains made of brick and contains grassy fields, all sorts of flowers, ponds (natural and manmade), trees varying in size (from small to incredibly huge) and essentially looks like a Venetian garden. It is invisible to outsiders. Its existence is only known by few people, including Ash, Misty, Brock, Bianca and Lorenzo. During the film, the thieves Annie and Oakley found out about the Secret Garden, snuck in and captured Latios and stole the Soul Dew. Havoc wreaked, and the stolen, corrupted Soul Dew was destroyed, and a huge tidal wave was about to destroy Alto Mare, but was stopped by Latias and Latios. Latios sacrificed himself in the process and became the new Soul Dew.