The Valley of Time is a rumored host to a legendary Pokemon over the power of time. It is a hidden valley in the Emerald Mountain and sports some of the oldest flora in the region. It has been untouched by many.
"Duncan, Drake, come. This is the Valley of Time, resting place for Dialga and Palkia, along with a home to the Pokemon Celebi. You see what I stand to protect even in my old age? You young children are obsessed with moving forward, why look at Naiya. She cannot even comprehend what's going on. Edana? Refuses to deal with those who want to move forward. Maku is content with the way things way..."
- Sora, to Duncan and Drake on what Minoru is and why she is a Gym Leader.