In the seventh century BC the Greeks of Gela established a commercial port, documented by the nearby necropolis of Montelusa (a hill west of the current settlement).
In the sixteenth century, Italian historian Tommaso Fazello noticed in the area of the mouth of the saxa quadrata the remains of the docks of the classic port that stretched along the banks of the river.
The port's activity and scale had to be intense considering the importance of the city, as evidenced by the significant number of coins found in the area ranging from the classical to the Byzantine and finally Arab period, confirming that the emporium was in use until about the 10th-11th century.
A huge Greek sarcophagus was also discovered near the church of San Leone, formed by a single block of sandstone, but was unfortunately cut into four parts and transformed into seats on the beach.
In the eighteenth century the enlightened bishop Lorenzo Gioeni (1730 - 1754) built a summer holiday home for young people that still today dominates the woods and the beach of Maddalusa from the top of the Montelusa hill.
The project was rejected for several reasons and in 1749 the works for the construction of the port were carried out in the beach of the Porto Empedocle, which had been fortified in 1544 during the reign of Charles V. In the 19th century, San Leone was once again populated as a holiday area by the people of Agrigento.
From the 1960s, San Leone witnessed uncontrolled development that has transformed it from a small fishing village to a chaotic seaside resort crowded during the summer by about 30,000 vacationers, while the stable population is about 4,000 people.
Little is left in the inhabited area as most of the finds have been either adapted for other uses or, as regards the port infrastructures still visible a century ago, buried by the gravel brought by the sea and by the floods of the river.
The Cannatello emporium functioned, as Monte Grande did in the 18th century BC, as a port of call for sulfur, rock salt and probably also bitumen for the Aegean-Cypriot navigators, who used this beach as intermediate base for the routes that connected Cyprus and the Aegean with North Africa and the Sardinian and Iberian West.