The two towers, Bologna's commonly recognised symbol, are strategically placed at the entry point in the city of the ancient Via Emilia (Aemilian Way). The seclusion in which they appear to us now, at the centre of Piazza di Porta Ravegnana does not correspond to the original layout with wooden buildings surround their base and hanging passageways.
Made of masonry, similar to few other buildings, they carried out important military functions (signalling and defence) as well as representing, with their grandeur, the social prestige of families of nobility. In the late 12th century, at least one hundred towers punctuated the city’s skyline, only twenty of which survived the ravages of fires, wars and lightning strikes, and are still visible today. Rather recently, the statue of San Petronio, sculpted by Gabriele Brunelli in 1670, was positioned in front of the towers, which had formerly been removed in 1871 "for reasons of traffic safety".
The Tower was built between 1109 and 1119 by the family bearing the same name and was handed over to the municipality as early as the following century. Measuring 97.20 metres in height, it has an overhang of 2.23 metres and an internal staircase containing 498 steps that was finished in 1684. The base is surrounded by a "rocchetta" (stronghold), which was built in 1488 to accommodate the soldiers standing watch. Today, underneath the arcade, some craft shops have been relocated, reminiscent of the mercantile functions carried out by the medieval "Mercato di Mezzo".
The nearby Torre Garisenda, contemporaneous with the previous one, is visually different due to its lower stature of only 47 metres and the steep overhang (3,22 metres) due to an early and greater subsidence of the land and the foundations. Dante, who once saw it still intact, compared it to the stooped over Anteo in the XXXI Canto dell'Inferno (31st Song of Hell). During the middle of the 14th century, it became necessary to lower it. The ashlar covering in selenite stone at the base dates back to the late 19th century.