Over the course of its history, the fifteenth-century Palazzo Mazzancolli, overlooking via Cavour, - which in Roman times was a segment of the decumanus - has seen its use change more than once - which has been accompanied by just as many structural adaptations. The historic building, which has housed the State Archive of Terni since 2002, was for almost two centuries the residence of the Mazzancolli family, one of the most influential in the city between the 15th and 17th centuries, which had among its major members Ludovico Mazzancolli, (bishop of Terni from 1406 to 1458) and his nephew Giovanni, belonging to the Roman curia. It was he who commissioned its construction, for which the structures of two fourteenth-century tower-houses were used, still visible on the facade in medieval ashlars, distinguished by the family coat of arms placed on the side of the balcony (an arm covered with armour whose hand holds a club placed on the neck). On the vault of the internal portico that surrounds the courtyard is instead the coat of arms of Pope Pius II Piccolomini, hosted by the Mazzancolli family in 1459. In the seventeenth century another local noble family acquired ownership of the building and remained until the nineteenth century: in this century the building, no longer inhabited by the owners, was rented by an entrepreneur from Ancona who set up a spinning mill and subsequently sold it to the Congregation of Charity. Restored in 1878 to a design by architect Benedetto Faustini, it housed the Monte di Pietà. In the thirties of the twentieth century, Palazzo Mazzancolli was purchased by the National Fascist Party who had it restored by the architect Gaetano Coppoli to use it as the "Casa del Fascio". The last restoration, which took over ten years, was completed in the early 2000s.