Yulin IV is the fourth planet from the sun of the Yulin system, Banu Protectorate. Tectonic activity on this world has raised towering pillars of rock with natural windows caused by constantly-shifting wind patterns. The Banu in the system utilize these natural formations as obstacles in starship races.
Geologists interested in observing these formations in person have been known to hire Smuggling Soulis to get them to the planet's surface without catching the attention of any Racing Soulis, who believe that their presence will interfere with the races.