Cividale del Friuli
The Natisone is formed at above sea level on the border between Friuli and Slovenia by the confluence of two streams: the "Rio Bianco" () and the "Rio Nero" () which spring from the Punta di Montemaggiore and Gabrovec mountains. Before the confluence with the Torre, it passes through the communes of Pulfero and Cividale del Friuli.