A mysterious lake that exists on a hidden mountain only accessible through the Steam Cavern. It is rumored a Pokemon sleeps at the bottom of the lake after a long battle with it's rival. The lake's temperature is off the charts, often steaming.
"Never come up here again. Do you hear me? Duncan! Brandon! Jenna! None of you should have came up here. This place is far too dangerous for children to play in. Now leave and let me make sure you have done us ill....
...Reshiram, here you sleep in the bottom of the lake. They don't know that's why it's so hot, why other pokemon won't live up here. I remember the battle that created this valley and scared the Eevee population away. So sleep, and never awake.."
- Sora, a flashback of her last visit to the Fogbound Lake.