Dragon's Valley is a canyon near the desert wasteland where Satou first appeared in the other-world. The wasteland has reddish-brown colored earth, Satou likened it with the American Grand Canyon.
Dragon's Valley was home of the Dragon God, Akon Kagura. The valley was accidentally demolished by three consecutive uses of [Meteor Shower] activated by Satou when he's being attacked by army of Lizardmen. As a result the Dragon God along with some dragons who ruled the Valley were killed in the process.
The valley is protected by a barrier of invisible force field.