Pausanias says that on the inner side of the embankment there flows a river, which, descending into a chasm of the earth, issues again at a place called Nasi (); and that the name of the village where it issues is named Rheunus ().
According to Pausanias, the river located within the embankment flows; it enters a geological fissure in the earth and reemerges near an area called Nasi (); the village where this river exits is named Rheunus ().