Collefontana-Fontana Liri Inferiore is a comune located in the province of Frosinone, within the Lazio region of central Italy. It is situated in the southern portion of the region, characterized by its position in the mountainous and hilly terrain typical of the area.
The municipality serves as a local administrative center for its surrounding rural landscape. While specific historical landmarks are not detailed in general records, it functions as a residential and agricultural community integrated into the regional infrastructure of southern Lazio.