The discovery of the lighthouse

So where was the lighthouse located? As we have seen, the ancient authors are quite specific: "In the sea itself Claudius constructed huge moles on both sides of the entrance and thus enclosed a large body of water, in the midst of which he reared an island and placed on it a tower with a beacon light". In the fifteenth century the remains could still be seen "at a great distance in the sea". The moles and the island are depicted on several drawings and paintings from the sixteenth and seventeenth century, with the lighthouse on an island in front of the passage between the moles.

The oldest reconstruction drawing that we have of Portus was made by Pirro Ligorio and published in 1554.
It led to this reconstruction, published in 1580 (Georg Braun and Frans Hogenberg, Civitates Orbis Terrarum).

In 1970, after some excavations at the occasion of the construction of Leonardo da Vinci airport, Otello Testaguzza reached a completely different conclusion. He recognized the remains of the lighthouse on top of the northern mole, to the east of the runways. He rejected the information provided by ancient and later authors. Wrongly, as it turned out later.

In the years 2004-2016 many deep drillings by Antonia Arnoldus-Huyzendveld led to the discovery of the location of the lighthouse. The lighthouse was a bit to the west of Viale di Coccia di Morto, much further to the west than had been expected in the twentieth century. And it was indeed on top of a little island, not between the end of the two moles, but a little further to the west. There is now a junkyard on top. The remains, consisting of tufa, basalt, and sherds, are at a great depth: -4.40 to -15.50 metres. The size of the basin of Claudius turned out to be more than 200 hectares. The northern mole was 1600 meters long, the southern one c. 1320.

The location of the two moles and the lighthouse on Google Earth (red lines).
Lighthouse.kmz for Google Earth (Antonia Arnoldus-Huyzendveld).

The location of the lighthouse-island. Photo: Jan Theo Bakker (2007).

The location of the lighthouse-island. Photo: Jan Theo Bakker (2007).

Building activity on the passage to the south of the lighthouse-island. Photo: Jan Theo Bakker (2007).