The Black Walls are large walls surrounding the innermost part of the city of Volantis. The only people allowed to dwell within them are scions of the Old Blood descended from Old Valyria, and none can enter without an express invitation from them. The Walls were formed from dragon stone by the dragonlords of Valyria when they first built the city, and are so large that on the annual celebration of its founding six four-horse chariots race along the battlements side by side.