The river source is linked to legends and popular venerations since ancient times. The river, with a series of cascades and waterfalls, runs along the Comino Valley and afterwards the Casalvieri, then it runs for 15 km in a deep gorge carved in the foothills of Mount Cairo after which it reaches the Liri Valley. The (Il) Melfa is called La Melfa, the female, in the popular dialect of the Comino Valley and is mentioned by Strabo. Some have linked the name to Mefiti, regional pagan deity, the goddess of men, shepherds and farmers and warriors, revered before the advent of Christianity in the valley. His cult is often associated with places with river water, lakes, sometimes sulphur.