In the 11th/12th century the defensive system of the city consisted of walls, towers and fortified bridges with gates to regulate access to the city. That “dei Seratti” was one of the gates of Pontremoli and through the Casotto bridge it connected the Imoborgo with the western bank of the Verde stream.

The bridge owes its name to the tower, a fortified building commonly defined with the term “Casotto”. The gate, built according to tradition by the Serattis, a family whose presence is documented in the Pontremoli of the fourteenth century, retains a good masonry with rows of sandstone according to a medieval masonry technique. The image of the gate and the bridge has been the coat of arms of the Municipality for centuries.

The Casotto bridge was originally called the “S. Francesco di sotto” bridge: it can easily be deduced that the construction of this and the homonymous “S. Francesco di sopra” bridge (or Crà«sa bridge) is closely linked to the construction of the church of S. Francesco. The presence of two similar bridges crossing the same stream instead testifies to the dualism between Sommoborgo and Imoborgo which was consolidating in those years. The current humpback bridge in masonry arches is the result of successive reconstructions. In 1391 a resolution (registered in the Statutes) established that the bridges of “Betula” and “Imoborgo” had to be rebuilt at the expense of the Municipality with masonry arches, built at the rate of one arch per year, continuing to keep the the wooden parts. P. Ferrari, on the other hand, recounts the reconstruction of 1496: “As regards this last bridge, it should be remembered that it had already been rebuilt on other occasions, knowing that, even in 1496, the year following the fire, the bridge «quo itur ad ecclesiam Sancti Francisci a Cazzaguerra infra», which had been «diruptus ac distructus», and the road was rebuilt «qua itur ad Sanctum Franciscum et Summum Verdenum»”.

Ferrari himself narrated the flood episodes of 1567 and 1569 which caused damage to the structure of the bridges and a considerable rise in the river bed: “the two bridges over the Verde were seriously damaged […] The same fate also befell an existing chapel on the lower deck, and which had been enlarged by G. Luca Galbiati in recognition of a healing obtained, and in which there was also an image of the Madonna painted on a wall: a small chapel which was later rebuilt and which also exists today at one end of said bridge.” The reconstruction of the lower bridge was long and tribulated and ended around the year 1573.

The current entrance to the bridge from the Porta dei Seratti instead dates back to the year 1834 when access was improved with the stepped staircase.

photos: arch. Elia Santini