The “Quadrilatero” area has an ancient tradition. It had its greatest development in the Middle Ages and kept  its trade vocation throughout the years. The main craft guilds of the city such as goldsmiths, butchers, fishermen, “Salaroli” (workers who salted meat to cure it), the Furriers, Barbers and the Society of Painters, had their headquarters in this area.
Most of the guilds located in the street once called Mercato di Mezzo, today known as via Rizzoli, at the beginning of the 20th century also moved in the heart of the Quadrilatero. Nowadays the Quadrilatero is the historical center area bounded by piazza Maggiore, via Rizzoli, piazza della Mercanzia, via Castiglione, via Farini, piazza Galvani and via dell’Archiginnasio.
Jewelers, butchers, delicatessens, greengrocer’s, bakeries, shops with traditional cuisine and craft activities and other specialized trades are located in these streets. Most of these shops have preserved the historic architecture and furnishing, thus making them genuine artistic treasures.  
From the high vaults, leaving behind the elegant piazza Maggiore, the path leads to the narrow and odorous alleys of the old medieval market with the characteristic “holes”. This is the commercial heart of the old town center, overflowing with goods on the stands that are scattered along via Pescherie and via Drapperie, and full of noisy sellers and customers going by.   
Text from "Botteghe di Tradizione e Pregio - Il Quadrilatero di Bologna" (Traditional and valuable shops - The Quadrilateral area of Bologna)