Cerea was a planet located in the galaxy's Mid Rim. It was a paradise largely unspoiled by the ravages of technology. It was the homeworld of the Cereans, including the Jedi Master Ki-Adi-Mundi, who served as a member of the Jedi High Council during the waning days of the Galactic Republic. Prior to being arrested on the Five Points system, Jyn Erso spent time bouncing around the Mid Rim on planets such as Cerea and Coyerti before settling on Takodana for almost a year. Cerea was home to big bipedal birds known as aryx, which the Rebel communications specialist Kidi Aleri rode.
The native Cereans were very protective of their homeworld's ecology, and thus only allowed off-world visitors and immigrants to enter and reside city-sized structures called Outsider Citadels. One such structure was Asphodar 3.
During the Cold War and the subsequent First Order-Resistance War, the Resistance ran what they called a "peaceful and nature-led deprogramming protocol" in the "beautiful and ancient forests" of Cerea, meant to rehabilitate defectors and prisoners from the First Order and counter the FO's ideological "brainwashing". Participants practiced daily meditation, stretching, and dance; ate an entirely plant-based diet; and abstained from most uses of technology. One such participant was First Order defector Archex, formerly Captain Cardinal.
In 34 ABY, the Resistance spy Vi Moradi picked up Archex from Asphodar 3 to accompany her on a mission to establish a Resistance base on the planet Batuu on the edge of Wild Space.