The failure of Monsummano’s thermal baths to adapt and the revival of nearby Montecatini’s thermal spa activity were among the significant causes that, beginning in the mid-1950s, led to the gradual change of economic policy and to Monsummano and its territory being defined as an essentially industrial district. The proliferation of industrial enterprises and the large increase in population followed the town’s growth, which was characterized by excessive building demolitions, traffic congestion, and a progressive loss of its urban form. This growth was particularly dramatic throughout the years 1960-1980. The town expanded mainly towards the south, where conditions were particularly favorable because of the availability of building sites, the presence of the renowned Grotta Giusti hotel-spa complex, and a good road system following the modernization of the old Via Francesca linking to the Valdarno. The town’s historical center—made up of three squares (Giusti, Del Popolo, and Amendola)—has remained Monsummano’s urban point of reference.