Prato della Fiera is a public space, a common and collective good, with more than 1000 years of history and still hosts, in October, the Antiche Fiere di San Luca, the oldest tradition still active in Treviso. It represents one of the last non-formalized open meadow-space in Europe. Until the Renaissance almost all cities had a space like this, natural, multifunctional, ready to host fairs, camps, hospitals, lazarets, temporary warehouses, spaces for haymaking and temporary cultivation. A participatory urban regeneration project promoted by Prato in Fiera aps has been underway since 2016.