Excavated during the reign of Cosimo I de’ Medici, probably in a period between 1563 and 1574-75, the "Navicelli" Canal connected the port of Livorno to the city of Pisa. The canal made it possible to avoid the mouth of the River Arno, considered inappropriate as a landing and seaway because of its strong currents. It was excavated starting from the Porta a Mare (seagate) of Pisa, near the left bank of the Arno, then reached San Piero a Grado, crossed the swamps of Coltano, touched Stagno, and then arrived at the port of Livorno in the vicinity of the Old Fortress. Control of the "Navicelli" Canal was entrusted to the Canals Office of Pisa, which Cosimo I reorganised in the mid 16th century. In 1595, Grand Duke Ferdinando I de’ Medici attended to restoring the canal, and in 1603 ordered the construction of the roofing intended to shelter the boats at Porta a Mare, and called the "Sostegno" (support). Still active until the mid 19th century, the canal thereafter fell into disuse. A fascinating project has been hypothesised several times to make the canal fully navigable again.