Colony One was the capital city of Ylesia. It was located on the shore of the oceanic Zoma Gawanga, between Colony Two and Colony Three. The Altar of Promises and the Mountains of the Exalted were nearby.
After Ylesia fell to the Yuuzhan Vong, it was renamed Peace City. It was the headquarters of the Peace Brigade, and was controlled by the Besadii Hutt clan. It contained slave barracks, the Palace of Peace (the headquarters of the Ylesian Senate), and a damutek for Maal Lah. Close to the city, slaves received their daily euphoria from a telepathic t'landa Til. It was there that Pwoe was found in a meeting with the Peace Brigade leaders.
When it was discovered to be the Peace Brigade's headquarters, it was invaded by the New Republic and Twin Suns Squadron. When the New Republic took the city, Senator Pwoe and Thrackan Sal-Solo were arrested.
- The Paradise Snare (First appearance) (As Colony One)
- The Hutt Gambit (As Colony One)
- Rebel Dawn (As Colony One)
- The New Jedi Order: Ylesia