The river that crosses this valley has its origin in Mount Fumaiolo. At its source it is called river Fosso Grosso. After flowing in a wide curve near San Piero in Bagno and Bagno di Romagna it forms Lake Quarto, an artificial basin that was created on the bed of a dried up lake. Another tributary, river Para, meets the lake at the same point as river Fosso Grosso.
An important tributary of river Savio is river Borrello that flows down Carnaio Pass through a narrow valley, towards the plain, and it meets river Savio close to the village that has been called after it. The valley is dominated by the beautiful massif of Mount Fumaiolo (1497 meters), a limestone massif covered by woods and pasture land. On the Tuscan side of Mount Fumaiolo river Tevere has its source. It is interesting to have a look at the typical rock formation of this area: cliffs of marly rocks, Verghereto's blueish gullies and Perticara's impressive peaks.
      Besides, it is worth visiting the valley's two strips of land that belong to the Foreste Casentinesi, Monte Falterona e Campigna National Park: 'wilderness' area of river Fosso del Capanno and Lama forest, a beautiful gateway to the park. Sarsina's "marmitte" (potholes) are another interesting phenomenon of this land: this is an erosion of the land caused by the course of river Fosso Lagaccio and river Fosso Molinello.
Nowadays the valley of river Savio is crossed by a fast freeway (E45) that has always been a key link between Romagna and Central Italy.
This valley is formed by two distinct elements indicated by the borders between the villages: Mercato Saraceno and Sarsina in the lower part; Verghereto and Bagno di Romagna in the higher course of the river.
Bagno di Romagna is a famous and old spa: probably the Romans were the first ones who used these baths. In fact, the 45° centigrade hot springs of Bagno's land are the reason that moved here the first urban settlement.
      Verghereto is located on an elevated place, close to Montecoronaro Pass and on an important hub that used to connect Romagna and Montefeltro with Rome. Sandstone manufacturing is a typical activity of Vergherto and its land.
Sarsina owes its fame to the figure of Titus M. Plautus, the famous Latin man of letters who was born here, and to bishop Vicinio, who was canonised, whose famous penance collar became through the years an effective device against the devil.
Mercato Saraceno rises on a high cliff, very close to Cesena. It hosts a number of important markets and until 40 years ago it played a key role as a sulphur mine.