Since the Medieval ages, the water has been the source of economic progress and prosperity. Bologna used to be the fifth biggest city by the number of inhabitants and the main centre of textile production in Italy during the 13th century. For many centuries, the water represented the main source of energy for manufacturing and commercial activities, especially mills for the production of silk (their models can be seen in the Museo del Patrimonio Industriale – Museum of the Industrial Heritage). So, it is not surprising that the Fountain of Neptun is the symbol of the city of Bologna.
Only some toponyms remain from a dense network of the old hydraulic system. All water canals were buried underground.
You can understand the importance and the presence of water in the city when waking through the significant places related to the water system of the city.
The itinerary starts at the Piazza Maggiore, passing next to the Fountain of Neptun, walking along Via Rizzoli up to Piazza della Mercanzia dominated by the Palazzo della Mercanzia. Then you take Via Zamboni, you turn left into Via del Carro, you pass under the “voltone” with a mask – antique gate of the old Jewish ghetto. The river Aposa runs under the ghetto. You take Via dell'Inferno on the right, you continue up to the small square “Piazzetta Marco Biagi” where you exit from the ghetto and you enter into Piazza San Martino.
On your right side, there is the entrance into the San Martino's church called “in Aposa”. After the visit of the church, you take Via Marsala on the left, then Via Mentana to arrive in Via delle Moline, one of the old canals of the city. On the crossing with Via Capo di Lucca, you can hear the noise of the weir of the water canal – its energy was used to run grain watermills on the Canale delle Moline. You turn back into Via Oberdan, then you take the first street on the right Via Bertiera and again on the right into Via Piella passing under the gate Porta Govese (called also Torresotto dei Piella). Passing under the gate, you arrive to a small bridge with a small window where you can see the water stream of Canale delle Moline.
At the end of Via Piella, you turn to the left into Via Righi, you cross Via Indipendenza, you walk through Via Falegnami up to Piazza della Pioggia where you can visit the Santa Maria della Pioggia's church. You continue through Via Riva di Reno, you turn right, you walk through Via Polese and then you turn on the left into Via del Porto. You cross Via Marconi and Piazza dei Martiri to join Via Don Minzoni where you find the old Salara (deposit for the salt), that is part of the area called today Manifattura delle Arti (Manufactory of Arts). From Via Don Minzoni, you take Via Fratelli Rosselli to the South, you cross Via del Porto again, then Cavaticcio canal, Via Azzo Gardino, the Park of the Ex-Manifattura Tabacchi (former Tobacco Factory) and you join Via Riva di Reno again.
On your right hand side, you can see the Church of Santa Maria della Visitazione or of Ponte delle Lame that once was surrounded by waters of the Reno canal. If you follow the Via Riva di Reno, you will find the Santa Maria della Carità's church. You cross Via San Felice to walk along Via della Grada until the headquarters of the Consorzi dei Canali di Reno e Savena in Bologna where you can find also the Santa Maria e San Valentino della Grada's church. You turn back to Piazza Maggiore, walking through Via San Felice or Via del Pratello and then Via Ugo Bassi.