Zaddja is a dry, hot world with scattered oases. The system was associated with high comet activity, and the comets’ trajectories would frequently intersect with the planet's orbit, bombarding its surface and creating massive craters. These impacts would encourage activity in subterranean waters and minerals, turning the craters, known to the locals as Caldera, into life-filled pockets on the planet's surface. Large, bulbous tree-like plants were scattered around these areas, which led to the growth of more flora in the surrounding land. The craters of fertile soil were heated by geothermal vents and became the location of the earliest colonies on Zaddja.

Beneath the massive craters is a system of magma streams and geothermal vents that power the cities and provided warmth during the freezing desert nights. Before the Clone Wars, the planet became a trading post for some of the Outer Rim Territories. The colonists lived in tiny townships which were the only form of civilization on the planet until the Clone Wars, which saw the Separatists use Zaddja as one of their major bases of operations in the outer rim.