Torre degli Azzoguidi, Medieval tower in Bologna, Italy

The Torre degli Azzoguidi is a medieval tower standing in Bologna that rises prominently above the surrounding buildings. The structure has a narrow, vertical form with thick stone walls and shapes the character of the old city center.

The tower was erected in the second half of the 12th century, not around 1150. The Azzoguidi, a Guelph family recorded in Bologna's chronicles from 1228, owned it; when the line died out in the 15th century it passed to the Muzzarelli. In the 19th century the selenite base was hollowed out for a shop, and a 1950s restoration consolidated the structure.

The tower's nickname Altabella comes from its height and perfect verticality, and the street beside the Cathedral of San Pietro is named after it. The Azzoguidi were Guelfs, and with the Galluzzi and Prendiparte towers theirs formed a triad of medieval skyscrapers placed at key points of the city. A small watchmaker's shop still occupies the base.

The tower is located near the Cathedral and can be reached from Altabella Street. A shop at the base provides easy access and helps visitors locate the site within the city.

A window on the tower is cut off by the present roof, and the walls at the base are about 2.28 metres thick: both suggest the tower was once taller than its 61 metres. In the 19th century the selenite base was hollowed out for a shop, and a 1950s restoration consolidated it.