In the 16th century, the architect Jacopo Barozzi was in charge of designing a port here at the beginning of the Navile Canal, along with a warehouse to store one of the most precious commodities of the Papal State: salt. Salt was transported down the Po and canal from the pans of Cervia on the Adriatic, and heavily taxed to top up the papal coffers—to the extent that Umbria, like Bologna part of the Papal States, started making bread without salt after a particularly nasty disagreement, just to show the pope what for.
The current Salara, which resembles a small fort, was built in the late 1700s when the former warehouse proved too small. In its day it held 8500 sacks of salt. Falling into disrepair after the port was abandoned in 1935, it was restored as the Cassero, an LGBT centre and club, and is now a part of the Manifattura delle Arti.
Image by Giovanni Dall'Orto, Creative Commons License