Viing Lok is the name of a colossal cavern of Vul Sahsir. It is so wide and high that dragons and other large winged creatures can comfortably fly here. The cavern roof, five miles high in some parts, is supported by stalagmites that go from ceiling to floor, with tens of thousands of them across the enormity of the place. Some of these are so large, that they hold the lairs of beats, monsters and humanoids. Over the epochs, dragons have shaped it so that they can more easily fly about Viing Lok enormous area.
In some areas, obstructions and other hazards have been destroyed by dragons or those serving them so as not to be a flying hazard. Since the area is rather dark, flying here has to be learned by practicing flying the area and remembering the safe lanes, because at full speed a dragon can easily overshoot its range of dark vision giving only moments to make a change before collision.