Moulis is a commune in the Ariège department in southwestern France. Moulis is situated on the D618 road, which follows the Lez river valle…Moulis is a commune in the Ariège department in southwestern France. Moulis is situated on the D618 road, which follows the Lez river valley from Castillon-en-Couserans to Saint Girons. Either side of the Lez valley, the land surface of the commune rises steeply to forested mountains, giving a height difference of 1200 m between the lowest point of the commune and the highest.