A new underwater route opened on Wednesday for divers, snorkelers and canoeists in the ancient Portus Julius in the underwater archaeological park in Baia, in the province of Naples. The underwater structures are submerged between two to five metres deep, due to the bradyseism typical of the Phlegraean Fields. In ancient times, the structures made up the large industrial and commercial district of Pozzuoli.

This is the section closest to the connection created between the sea and Lake Lucrino where boats coming mainly from Egypt and the East could unload their goods for the Rome market. In ancient times there were dozens of warehouses at the port, which will now be visible through the new underwater route. The route, called the "Path of the Columns", contains numerous remains of columns, both in marble and stucco.