Palazzo della Mercanzia is located in the area where the old city customs used to be. On its left, the ancient palaces with wooden porticoes may be found (they recall the medieval aspect of Bologna) and from there, Torre Alberici (Alberici Tower) may be seen. The Alberici family built the tower in the 13th century. Unfortunately, its height (27 metres) has been hidden for a long time by a big and obscuring building. It was only in 1928 that the nearby houses were renovated thus giving the Tower the old visibility.
Fortunately, at present the evocative shop with wooden enclosures may be seen as well. According to some historians, it is the oldest one in Bologna, dating back to 1273. The walls of the tower were impoverished to make the inner area bigger than before. This let us think that the tower was even higher in the beginning. It may be possible that it was later reduced to make it lighter, when also its peak was turned into a turret. On the tower façade the traditional putlog holes may be seen: some of them were used for scaffolding, others were used to support the wooden beams on which walkways, staircases and attics were built; their purpose was to connect the various floors of the tower, or to connect the tower with the nearby houses and towers belonging to spouses or other families.
Source:Bologna la selva turrita (in Italian) enhancement project of the historical-architectural Bologna's heritage supported by the Fondazione del Monte.