(Torre Accursi) Accursi Tower, also known as the Clock Tower, is located in Piazza Maggiore. The owner of the tower was Accursio, a young man who had moved from Florence to Bologna to study law. After becoming an important jurist, he decided to have his own house built: the building was very big and included both a school, whose portico looked out on the square, and a corner tower.
The tower was added later to Accursio's house and after his death, it was bought by the growing Municipality of Bologna. On the façade of the building, a huge mechanical clock was added in 1444. Its initial aim was to mark daytime, mainly midday, but since 1451 it has also marked nighttime. In order to build the clock, the tower was partly modified and a little tower was added. After being seriously renovated between 1885 and 1887 by Raffaele Faccioli, the Renaissance parapet was removed ans replaced by a group of bricks considered to be more suitable for the new medieval aspect of the building. As a matter of fact, today's portico under Palazzo D'Accursio (Accursio Palace) is quite new.
Source:Bologna la selva turrita (in Italian) enhancement project of the historical-architectural Bologna's heritage supported by the Fondazione del Monte.