In the heart of the Borgo Teresiano of Trieste, halfway between the Central Station and Piazza Unità, there is a stretch of water that bears the name of Canal Grande, also known as Canale Ponterosso.
Designed and built by the Venetian Matteo Pirona, between 1754 and 1756, the name grande was not given to praise its dimensions, which are not imposing, but to distinguish it from the Canale Piccolo which in the past allowed transport to the city ancient. It was built by digging the main collector of the salt pans, buried to allow the urban development of the city outside the walls.
In ancient times, the Grand Canal had a greater extension and went as far as the slopes of the church of Sant’Antonio Nuovo, then buried in its last stretch with materials from the demolition of Cittavecchia in the 1930s. A legend has it that a torpedo boat was incorporated into the landfill that had been lying there, in failure since the end of the war.
Warehouse-houses overlooked the canal, in whose warehouses on the ground floor goods brought by boats of various types were stored, together with the innermost warehouses, now destined for shops and garages for cars.
It is also known as the Ponterosso Canal from the name of one of the three swing bridges that originally crossed it (Ponte Bianco, Ponte Rosso and Ponte Verde), the structure of which can be seen in a print from the end of the 19th century at the State Archives of Trieste.
Under the Ponte Rosso there is still a hygrometer carved in stone and graduated in Parisian feet and inches, potentially dating back to 1785, and whose zero, no longer visible, is known as Zero Ponte Rosso and finds its importance in indicatively representing the level of the low tides of two centuries ago, evaluating it as the oldest in the set of fundamental zeros present in Trieste.
In its waters, an interesting variety of marine flora and fauna can be observed with the naked eye.