Cavalciotto is a weir located in Santa Lucia dating back to the 11th century and a key component of the complex water system in Prato, consisting of 53 kilometres of millstreams that start here, cross the whole area of Prato and finally flow into the Ombrone River. The main function of the Cavalciotto was to divert the natural course of the Bisenzio River and create the so-called Gorone, the first and largest millstream in Prato. Originally this complex hydraulic system was probably made to reclaim the large marshy plain extending south of the centre of Prato.
Through the years it was consolidated, reinforced and used for drainage, irrigation, defence and, most importantly, as hydraulic energy powering initially 58 water mills and, in later centuries, manufacturing plants such as metal works, paper mills and, above all, textile factories. Cavalciotto is one of them most important local examples of industrial archaeology.