There are some ruins in the Valley that predate all living and historical memory. It is said that humans have walked the world for three thousand years, but the Blackwall is older. Much, much older.
It lies in the heart of the Valley of Bones, a sheer and smooth wall of reflective obsidian. Viewed from a certain distance it appears to cut off access the the Granite Hills beyond, but with good navigation is can be easily bypassed, as the hills stretch for miles beyond it’s length. However, determining exactly how long the Blackwall really is is not an easy question to answer.
Those who have tried to walk its length have found it impossible. Days pass and the monotonous sands whistle by, but the wall seems to have no end. But how can something that is finite when viewed from afar be infinite from up close? What does the wall guard or screen off? Its construction must have taken an age in itself, and yet it seems to shield nothing from nothing.
Locals avoid it. Explorers are confounded by it. Only the truly unlucky might unravel it’s secrets and the treasure that unlocks the ancient ways into the world lost for generations.