Planet of Geonosis
"Who'd want to go to Geonosis? It's nothing but a bug's nest!"
Geonosis had a large diameter but light gravity and dense atmosphere. With a weak magnetic field, harsh solar radiation storms and massive sandstorms were common, and on occasion mass extinctions occurred. The most persistent surface organisms were humble red rock algae while the semi-insectoid Geonosians were driven underground. The planet consisted of a diminutive molten core with a rocky mantle forming a rocky, desert world subject to flash floods that carved great highland canyons. Water made up 5% of the surface.
During the time of the Geonosian rule, much of the planet's architecture was similar in appearance to termite mounds, consisting of domes and buildings built into caverns and rock spires. Therefore, one could easily mistake Geonosian buildings for natural formations and the planet to be uninhabited, a great asset during war.
