Castello di Colle Massari, Medieval castle in Cinigiano, Italy.

Castello di Colle Massari is a fortified rural complex on a hill at 310 metres above sea level, south of Sasso d'Ombrone and between Poggi del Sasso and Vicarello. Three buildings stand on three sides of a quadrangular courtyard entered through an arched gate in the curtain wall. Two of the four corner towers survive; the south-eastern one collapsed in the 19th century after a landslide, leaving only traces.

Colle Massari likely began in the 13th century as a rural house, later fortified, near the documented pieve of Sant'Ippolito a Martura (1148). In 1294 Gullielmino Buonsignori bought the castle from Siena after Aldobrandeschi decline. Fabio Piccolomini sold it to Grand Duke Francesco I de' Medici in 1586; in 1630 it passed to the Patrizi marquises, who held it until the 19th century.

The estate functions as a working organic wine and olive oil producer, where visitors can observe traditional Tuscan farming practices in action within the castle grounds. The integration of medieval stonework with current agricultural work shapes how the place is experienced today.

The property offers overnight stays in rooms and villas, plus cooking classes and wine tastings that let guests experience how the estate operates. Spring and autumn are the most active seasons when farming work is visible and the weather is comfortable for exploring the grounds.

The name comes from the Latin massarius, the medieval administrator of an agricultural estate centred on a farmhouse (massa). The castle's own massaro likely managed a small plot dependent on the nearby castle of Sasso d'Ombrone. The chapel of Santa Marta inside the complex, built in the 17th century, replaced the vanished parish church of Sant'Ippolito a Martura, documented from 1148.