Azzoguidi Tower (also known as Altabella Tower) is located in Via Altabella (the street was given this name because of the presence of the tower). It is 61 metres high and it's prossible it was even higher in the past (its façade seems to have been designed to counterbalance the height of the building).

Azzoguidi Tower is an example of the typical medieval bolognese towers: square-shaped base, ten rows of plaster parallelepipeds, an ancient pointed arch door on the ground floor and a little opening leading to the nearby flat (in Via Caduti di Cefalonia, this room was later used as a little chapel whose frescoes were painted by the 15th century Bolognese painters).

From their towers, not far from each other, the Azzoguidi and the Prendiparte families used to watch over St. Peter's Church and at the same time to safeguard the power of the Guelphs dominating the city between the 13th and the 14th century. Their role was not to fight but to rule over Bologna.

In 1500 the tower was acquired by the Muzzarelli family and it was given the structure of all the other towers in Bologna: used as a house on the first and second floors, empty upstairs and the seat of a shop on the ground floor. When the shop was built, the tower underwent some awkward works: the walls were empoverished thus undermining the tower's stability and the little entry door was enlarged thus severely altering one side of the tower's façade (the side in Via Altabella). In 1951 it was carefully renovated in order to solve these problems. Thanks to these renovation works, today's aspect of the tower is more similar to the original than during the Renaissance. First, its depth was restored, second the external part was improved after it had been damaged by the presence of severals shops, last the entry door situated in Via Altabella was given its original proportions.  Source: Bologna la selva turrita (in Italian) enhancement project of the historical-architectural Bologna's heritage supported by the Fondazione del Monte.