Prato (which means "field", for the flat local landscape that was once used for cultivation and grazing) is the area alongside the northern shore of the old lake, in an especially advantageous position for catching the sun and the flat terrain.
This zone is distinctly humid which has always created problems for the settlement, with the exception of the edges of the gentle sloping area where Piazza Granda extends. The Palazzo Assessorile has traces of gutters and drains constructed around the old tower, which was reconstructed wider and more solidly in the 1300s due to ground sinkage, probably of hydrogeological origin. Prato represents the natural continuation of Spinazzeda moving towards the nerve centre of Piazza Granda. The two roads arriving from Spinazzeda and Pez converged here, one continuing towards the castle vaults and the other towards Dres. The double convex arch shape makes it seem more like a cross-roads than a piazza for gathering and socializing, but its strategic commercial function remains very obvious still today. The piazza was overseen by a tower that was later to become Palazzo Assessorile in the 1400s, while the buildings alongside Corso Dante derive from the 1800s and are known to be built on wooden piles to compensate for the poor technical characteristics of the terrain. In ancient times the humid zone extended up to the current day Oratorio, where archaeological traces have been found of a boat jetty from the Rhaetian period, standing at the end of the narrowest cove of the old lake. The existing Via Martini connected Piazza Granda directly with Pez, with Via Marconi being a recent construction connecting to Via Trento and definitively downgrading the importance of Piazza Granda as a through route. The construction of Viale Degasperi completed the new urban design of Cles, allowing the district of Prato to assume a leading urban role in the town partly thanks to the presence of all the main public institutions. Via Filzi is one of the most important roads in Prato, leading as always to Caltron, and it was initially used for the construction of stately homes, followed by the development of a new residential district in Via Chini overlooking the old town centre, creating a new internal road system. The district terminates towards the north with the substantial zone of Piazza Fiera, the northern gateway to the town, again influenced by various changes in use over the years.
