 From here on the roads descents following the course of the narrow Tronto valley.Soon after Amatrice and Accumoli, the road leaves Lazio and enters the region of Marche.Passing through Arquata del Tronto (780 metres on sea level) and Acquasanta Terme (390 metres), SS4 keeps descending until it reaches province capital Ascoli Piceno (150 metres on sea level).