Csilla was a cold, ice-locked planet located in the Csilla system of the Unknown Regions, at the coordinates F-8 on the Standard Galactic Grid. Its capital was the city of Csaplar, which was mostly located underground.

Visitors to Csilla, whether Chiss or alien, were led to believe that the planet remained vibrantly populated despite its shift to much colder weather. The parts of Csilla near the Csaplar spaceport were bustling, with hotels, entertainment venues, merchants, diplomats, government and military business nearby. However, most of the above-ground parts of Csaplar and other cities were devoid of inhabitants and made to simply look lively to create the appearance of a well-populated world.

At the twilight of the Clone Wars, approximately 60–70 million Chiss still lived on Csilla. The vast majority of them lived in illuminated and heated underground caves which could even have forests, lakes, mountains, and convincing artificial sunlight within them. To create the façade of 8 billion inhabitants on Csilla, some of those who lived underground were selected on a rotating basis to spend a limited amount of time on the surface, to appear as if they lived there.