The first news concerning this fountain is found within a petition from 1352 in which the citizens of the Third of the City request the General Council to construct it. The citizens assumed the expenses for the construction and simultaneously obligated themselves to pay the overflow into the valley of the Montone, where the city's mill was located. However, the works were not completed until 1359, when the fountain took its current form below the road level of Via del Casato di sotto. It features a large vault supported by purely decorative semi-columns and closed by a brick parapet.