The Cistercian monks, who settled in Chiaravalle in 1153, began a reclamation work in the XII century that deeply marked the environment, transforming areas once swampy into highly productive soils.

The work of the Cistercian monks, and later of the Umiliati, allowed to transform that “land of marshes” into an intensive and specialized agriculture, thanks to the creation and exploitation of a network of irrigation channels and fountains for extensive irrigation and also thanks to the cultivation of rots. The rots are an agricultural system that exploits the water of the springs allowing continuous production cycles, without seasonal stops. In fact, it is a system that allows the cutting of grass even nine times a year, ensuring a continuous production of fresh fodder for cattle farms.

 The precious resource of the Fontanili in the territory of San Donato Milanese now includes a single march of about 30 hectares, located between the Milan-Genoa motorway and the Bagnolo farmhouse, which is an element of significant natural interest. The reclamation work continued practically without interruptions over the following centuries, ending only in the nineteenth century and devoting the territory of San Donato to agricultural exploitation.