The Portico di San Luca was constructed between the seventeenth and eighteenth centuries to shelter and facilitate Byzantine icon of the Madonna which is brought down to the Cathedral of San Pietro from the Basilica every year.
This takes place during the Feast of the Ascension. The icon has been worshipped since the twelfth century and it dates back to the tenth or eleventh century. Bologna has a network of roofed arcades nearly 40 kilometers long.
One of them that lead to the sanctuary of San Luca is the longest in the world, its length is 3.8 kilometers and it stands at a height of 300 meters above the city.