From the introduction:
A desolate sand waste on the coast of BloodStone Isle between a bay full of seagrass shallows on one side and the nightmarish Ragma Rift on the other, the BoneDust Dunes are more isolated and less forgiving than any other region of BloodStone Isle. Constant dry wind during the hot season and centuries of trampling by the tortoise-like Kralings have left a morass of chalky powder in a vast dune field that is difficult to traverse and nearly impossible to navigate. The BoneDust itself is fine, choking, caustic sand that pervades every square inch and crevice of the Dunes, making travel a blinding and staggering affair. When driven by wild Tempest winds, ghastly electrically-charged haboobs can blacken noon skies and drive every inhabitant under any available cover. Under more normal circumstances, the lack of fresh water, scorching wind and inevitable dust everywhere discourage visitors. These badlands have sifted out all but those singularly independent tenants of Dyar and its surroundings who cling to every scrap of freedom, because few would come so far out into the treacherous sands to attempt to take it from them.