Surrounding area

The Merse is a Tuscan river which originates in the Colline Metallifere, from the springs between Poggio Croce di Prata and Poggio di Montieri (848 m above sea level). It flows between the provinces of Grosseto and Siena, in a northeasterly direction in the first half of its path and toward southeast in its second tract, covering approximately 70 km through copse woods before flowing into the Ombrone at Pian di Rocca, near the springs of Bagni di Petriolo. In Pontiella the Farma stream, its tributary to the right which also originates in the Colline Metallifere (in Torniella) joins it; a few kilometers after it flows into the Ombrone as its tributary to the right.

The Val di Merse is the green valley spanning between Maremma, the Crete Senesi and the Val d'Orcia. It is a natural bridge between the Amiata and the Colline Metallifere, between the sea and Siena.

It is a body of water which flows through a beautiful backdrop of forests and monuments, including the splendid Gothic Abbey of San Galgano which dates back to 1218, that make it a beautiful itinerary for the people of Siena. Along its banks two natural reserves were established: the Alto Merse Natural Reserve and the Basso Merse Natural Reserve .

Worth noting are the “bathing” area of Brenna, one of the small internal lakes of Italy's ancestors, and the “mulino bianco” (white mill) of the well-known food industry of the same name, located on the bank upriver. The mill is the Mulino delle Pile, built in the early 1200s by the monks of the nearby Abbazia di Serena.

The Montagnola Senese is one of the hilly areas of the Province of Siena. Its territory spans the cities of Casole d'Elsa, Monteriggioni, Siena and Sovicille.
Its characteristics include copse woods where live oaks, oaks and maples abound. In higher elevations, chestnuts are found. The undergrowth is rich with juniper, honeysuckle, cistus, holly and arbutus. The highest point is Montemaggio which rises 671 meters above sea level.
The subsoil, primarily chalky, is rich with marble. This includes the famous yellow marble which, beginning in the 13th century, was used in the construction of many churches in the area and beyond, seeing that it was also used for the Duomo in Florence and the Duomo of Orvieto.
It is laden with carsic grottoes (more than 80) and water-bearing strata which guarantee water supply to the various towns in the area and in Siena. Near the Pieve di Molli, in the city of Sovicille, the Elsa begins. It is one of the highest points of the Montagnola and the Pieve di Molli is found on the watershed which divides the basin of the Elsa from that of the Merse.
Despite some areas that are difficult to traverse, the Montagnola territory is crossed by the Via francigena which linked northern Europe to Rome. In this section it links the nearby towns of San Gimignano, Colle Val d'Elsa and Monteriggioni to Siena. Proof of this are the beautiful country churches which are found there, such as the Abbadia a Isola found in the city of Monteriggioni and the Pieve di Ponte allo Spino, in the Sovicille area.
There are also numerous castles in the area, such as the Castello di Montarrenti.
Thanks to its natural, historic and artistic traits, it is a Site of Community Importance as defined by the EC directive 92/43 CEE.
 

The Terme di Petriolo are part of a Tuscan hot spring. They are located in the Valle dell'Ombrone, along the Farma river, on the border of the cities of Monticiano and Civitella Paganico, respectively in the Province of Siena and in the Province of Grosseto.
The Terme di Petriolo were already known of in Roman times, so much so that they were cited in an oration by Cicero and in an epigram by Marziale. In addition artifacts from the Etruscan and Roman eras were found in the area, both in the direction of Grosseto as well as toward Siena. Its current name, however, dates from the 1200s.
During the Renaissance, during the 1400s to be exact, the first hot spring complex was built in stone facing the northern bank of the Farma, in Monticiano city territory. The structure has a fort-like appearance, with walled structures in stone and loggias. It was precisely during the Renaissance that the springs became considerably prestigious, so much so that members of the Medici and Gonzaga families went there, as well as Pope Pius II.
The hot spring waters flow at a temperature of 43 degrees Celsius (110 degrees Fahrenheit) along a portion of the Farma river and are classified as sulfurous, salt-sulfate-bicarbonate-alkaline earthy hyperthermal waters.
The hot springs can be enjoyed both freely as well as within highly-equipped hot spring establishments annexed to hotels.