The Gobbo Bridge, also known as the Old Bridge or, indeed, the Devil's Bridge, is a construction of Roman origin which has undergone numerous renovations over the centuries. The building above dates back to the 7th century but traces of an older bridge have been found underneath, prior to the arrival of Colombano. The bridge, which is characterized by an undulating shape, the irregularity of the arches and the fairly narrow roadway, is 280 meters long and joins the two banks of the river through a complicated succession of 11 irregular spans, which differ in span and height, creating an up and down path that runs from one end to the other. The Bobbio Bridge, today used only as a pedestrian crossing, is the very symbol of the city of San Colombano, as well as one of the strangest and most original architectural structures in Italy.
Until the 16th century the bridge was made up of a few arches: a large arch on the right bank of the Trebbia with three smaller arches. Over the years, the floods of the river have inflicted several wounds on the stone bridge, which has always been patiently rebuilt, even with substantial modifications, to improve its safety and sturdiness. Around 1590 it began to be extended towards the left bank, based on a design by the master Magnano da Parma, and during the 17th century the bridge came to have 11 arches.
For centuries the bridge was a destination for pilgrims and religious processions: crosses and votive images were built on the banks below, some of which are still visible today.