It was erected in 1307 by the Bolognesi, when they dominated the entire town. The building, recently restored, has a square base, measuring 11, 07 x 12,76 m, all in brick, with five floors and a Landing, lighted by narrow Windows and two large Windows, on the third floor of the noth side and on the west side, and four openinigs on every side of the Landing, with Guelph battlements and a wide, wooden trussed roof, which existed already in the sixteenth century. The height from the eaves measures 38,13 m to the ground, and on the South-western side the tower leans for about 75 cm At the fortress, the ruins of one the castle doors with a wide, round, brick arch, called Porta Sant’Adriano (Saint Hadrian’s Doors), in honour of Pope Hadrian III, who died nearby in 885, still survive. Inside the tower you can visit the Museum of Nonantola: the four floors of the Museum tell the story of the town, by following an inverted chronological order that starts from the contemporary age to the Bronze Age, focusing on three key strands: the evolution of the town changes in the landscape and in the development of the local community.
At the groundfloor on the left side you can notice the tablet that remember the construction:MCCCVII-IND.V./HOC LABORERIUM FACTUM/FUIT TEMPORE DOMINORUM FRAN/CISCI DE ROTIS ET GUI/DONIS DE RECEPUTI DOMINORUM/NICHOLAI DE PLASSTELIS/FRANCISCI DE BENTEVOGLIS GO/CADINI DE GOCADINIS ET IOHANNIS DE/BATUTIS NOTARIORUM ET OFFI/CIALIUM OFFICIO MUNICI/PIIS CASTRORUM COMMUNIS BONONAE. (“1307 Indiction V. This construction was built at the time of the Lords Francesco dei Roti and Guido dei Receputi, and of the Lords Nicola dei Riastelli, Francesco Bentivoglio, Gozadino dei Gozadini and Giovanni dei Batuti, nobles and officers of the castle of thev Commune of Bologna”). Beside there are illustrations of the tower evolution because it was used for different purposes during the centuries: from defensive tower to warehouse to water tower. Going up the stairway it is possible to get an all-embrancing, breath-taking, view of the Po Valley, with a glimpse of the Ghirlandina steeple of Modena and, Modena and, on clear days, of the Whole chain of the Modenese Appeninines with, in the very centre, the pyramidal peak of Mount Cimone, the slopes of Como alle Scale, to the east and the Libro Aperto, to the west.