The Due Torri or two Towers,in English, are found in the centre of Bologna. The seven major roads of the romanesque town spiral outward from the foot of the towers.
The two towers also known as the twin towers are a pair of the few remaining built in the 12th century. The Rich families dedicated themselves to building towers as there was a competition to see who could build the tallest.
Asinelli the tallest of the two is 97.2 metres high and was built between 1109-19 by the Asinelli family.
Garisenda is nearly 50 metres tall, however its summit leans out 3.4 metres towards the east. On a par with other Italian buildings such as the leaning tower of Pisa. Garisenda was built in 1110 by the brothers, Fillipo and Apo Garisindi. Ever since its construction started the tower has been cursed with bad luck because the tower was supposed to have reached the same height as Asinelli except its construction had to come to a halt due to the tower's inclination.
In 1335 the tower was lowered almost 12 metres by Giovanni da Oleggio because it was considered a danger to the public. The demolition was carried out on the order of Giovanni Visconti who was the signore pf Bologna at the time.
In 1912 Profesor Francesco Cavani from the University of Bologna began studying the movement of the towers. He used an 80 meter piece of string with a weight on the end as a plumb line. By measuring the displacement of the pendulum 3 times a day for a year he discoverd that the Asinelli tower can move up to 3 centimetres in one day.
In more recent times the foundations have been reinforced and it is now safe to climb to the top of the Asinelli to experience a panoramic view of the city and it only costs 3 euros.