The small harbour is located in a protected inlet separating the promontory of Gianola from Monte di Scauri. It is improperly called ‘Roman’, since it was made in 1930 by Marquis Carlo Afan de Rivera, owner of an extensive estate on the Gianola promontory, to allow the mooring of his boats and the fishing boats that customarily found shelter there.

The structures now visible form two arms that converge in a central opening, delimiting a trapezoidal-shaped basin. The piers and docks are of local limestone bound with mortar, while the steps and mooring devices are of shaped stone. The harbour was built by incorporating the perimeter walls of a Roman fishpond used for fish breeding, which had internal walls and a complex system for exchanging brackish water with spring water. The fishpond was part of a sumptuous maritime villa with terraces and porticoes, which occupied the promontory of Gianola and is traditionally attributed to Mamurra, a dissolute Roman knight of Formian origin, who lived in the 1st century BC. He was a close collaborator of Caius Julius Caesar and followed him on his campaigns in Gaul, where he became immensely rich.

The erroneous attribution of the site to a small harbour instead of a fishpond is also linked to the traditional name of the place, Porto di Giànola, found in a deed of 1391, published in the Codex Diplomaticus Cajetanus, in which it is written ‘portum Janulae prope Scaulum‘ (i.e. Scauri). 

The small port of Gianola is included in the area of the Riviera of Ulysses Regional Park.