The actual village of Serdinya is located on the left bank of the Têt River The municipality of Serdinya is made up of several small hamlets: Les Hortals, Joncet (higher in the valley), Flassa (at the top of the mountain called “La Soulane”), Marignans (higher to the east) and La Guardia (to the east).

Located on the heights of Serdinya, the hamlet of Flassa has a remarkable church, called St Marcel de Flassa, restored in part thanks to the Serdinya-Joncet heritage association.