With the promotion to the rank of municipium, a phase of great building fervour began on the pre-existing Samnite settlement to which urban and monumental forms were bestowed. To ensure the water supply, it was decided to exploit the natural outflow of water caused by the slight slope of the land; on this orientation the Forum was built, the large paved square with a trapezoidal shape bordered by two drainage channels placed on the east and south sides so that, following the slight slope of the surface, rainwater was conveyed into the large sewer below the pavement. It is no coincidence that,not far from the junction with the pipeline, along the north-eastern side of the Decumanus, we find the industrial districtthe public baths, the splendid Fountain of the Griffin with the stone manhole cover and the mill, a structure consisting of a rectangular pit in which a water wheel was placed manoeuvred by a jet of water. A system of small sluices with stone guides determined the pressure necessary for the movement of the grinding wheels arranged in the compartment behind the pit, which produced energy that could be used for different features and purposes.