Used extensively since late antiquity, the salt pans grew in importance throughout the 1700s, and in the early 1800s the first plan to reorganize salt mining was implemented. Later, starting in 1920, there was a further boost with an overall design intervention, mostly the work of the director of the Salt Pans, Engineer Vincenzo Marchi, who served until 1934. It includes the construction of an industrial agglomeration of great importance for the time, shaping itself as a real city: there are the church, management, power plant, machine shops, carpentry shop, water reservoir, selected salts building, dockyard, barges maintenance yards, after-work theater, potash and bromine salts extraction plant, and employee buildings. The building complex is completed by the imposing salt warehouse at the outer entrance to the San Bartolomeo Canal.
The history of construction techniques can also be read in the remains of the iron bridges, the Rollone wheel installations (later an electric water-scooping machine), and the remains of the railway system for transporting salt to the embarkations by means of convoys made up of small wagons, replacing the original practice of animal traction.
The unique and striking Salt City has come down to us in good condition as a testament to one of the best industrial achievements of the early 1900s.