The Municipality of Castelnuovo Val di Cecina lies on the southern edge of the province of Pisa on the border between the provinces of Siena and Grosseto. The hilly landscape typical of the Cecina Valley is even more accentuated in this area: thick woodland lines the hills and the Mediterranean vegetation gives way to Apennine vegetation (chestnut, Turkey oak and Hornbeams). The urban settlements are concentrated in Castelnuovo and the villages of Sasso Pisano, Montecastelli Pisano and Leccia: four medieval hilltop settlements with the characteristics of the look-out posts of Lombard origin.

Castelnuovo is 576 metres a.s.l. and has a pleasant climate in the summer, while in winter the houses can rely on the geothermal energy that is harnessed both to heat buildings and, especially, to produce clean electricity. Still visible are the natural geothermal phenomena, fumaroles and gases.

This area of Tuscany is characterized by the natural geothermal phenomena commonly known as “lagoni”, especially around Sasso Pisano. They were already well-known to the Etruscans and Romans, during the Middle Ages the “lagoni” were largely exploited to produce alumen and sulphur.

In autumn and winter the hunting season and the season for picking mushrooms and chestnuts begin. In the community chestnut woodland, near the village, one can relax in the picnic area and read the didactic panels showing how historically chestnuts were processed and their various uses. In the old and new areas of the village there are numerous shops and other facilities. There also is a free WIFI net in some areas of the village.
The medieval borgo, still untouched, is little changed architecturally from the medieval period. The narrow alleyways paved in stones and full of twists and turns, the medieval gateways and the views over the valley characterize this welcoming ancient village, surrounded by woodlands. You cannot enter by car and thus this area is peaceful and quiet. One of the 12 nature trails created by the local Town Hall and the CAI of Pisa, allows you to visit the borgo to find for example the Chiassino alleyway (only 46-cm wide), and to proceed into the surrounding chestnut woodlands and down to the valley of the Pavone stream where it is possible to admire two bridges dating to the Renaissance period, Ponte Alto and Ponte del Defizio.

SASSO PISANO
The ancient village of Sasso Pisano lies on top of a rock in the vicinity of the springs of the Cornia river, at the summit its parish church dedicated to Saint Bartholomew is to be found. From here it is possible to see the scattered fumaroles and geothermal gases that are clearly visible following a nature trail . Near the Villaggio Boracifero the didactic trail created by ENEL is located, where you can admire the particularly fascinating geothermal phenomena. Here the small chapel and the village built in 1958 and designed by the architect Giovanni Michelucci are well worth a visit. In the neighbourhood, very hot thermal springs are situated (over 60°C) that create natural pools and supply water to a public wash-house next to the sporting facilities, and last but not least to a thermal pool made up of two pools at different temperatures and a bio-lake . In the village you can visit the small archaeological museum “Il Canapaio”, situated on the road to Leccia, where the archaeological items coming from the ancient thermal baths, dating from Etruscan and Roman times, are kept. Opening soon a museum dedicated to traditional Tuscan Arts and Crafts.

MONTECASTELLI PISANO
From the top of this village, a charming view overlooks the valleys of the Pavone stream and Cecina river. The most interesting buildings are: the Pannocchieschi Tower and the Romanesque church of Saint Filippo and Giacomo. The urban structure is typical of that of the medieval villages. Circular with parallel main streets linked to each other through narrow covered or uncovered alleyways.
In order to gather together and preserve the traditional tools of country farm life used between the end of 1800 and the beginning of 1900, the Museum of Rural Life has been established. A stone’s throw from the provincial road, the Etruscan tomb “Buca delle Fate” (8th century BC) is well worth a visit. On foot or on the back of a horse, one can enjoy the fascinating nature trails through the surrounding woodlands, along the Pavone stream.

LA LECCIA
Leccia is a very small medieval village which lies in the Cornia Valley on the road from Sasso Pisano to Larderello. Close to the hamlet, at the cemetery, there is the Santuario della Madonna del Libro built in Peruvian style by Matteo da Leccia.