San Giovanni di Duino is a small village near the Timavo source, situated on the crossroads of the national roads for Trieste-Monfalcone and Gorizia/Nova Gorica.
In Roman times, San Giovanni di Duino was famous (Station Fontis Timavi), as the Lacus Timavi port was nearby and from here roads ran towards Goriška, past the Karst towards Vipava, to Trieste, Istria and Dalmatia and to Aquileia, Friulia (Pianura del Friuli) and Venice. The Slavs settled here during the time of the Great Migrations. The Benedictines built a monastery here in the 6th century (which later became the centre of the Christianization of eastern countries). The Church of St John (San Giovanni in Tuba) was a popular centre for ancient pilgrimage. Being at the crossroads of several different routes, it was destroyed and rebuilt many times.
The port of San Giovanni di Duino was economically important until the emergence of the liberated port of Trieste at the beginning of the 18th century.
From then on, San Giovanni di Duino started to deteriorate. It was finally burnt to ashes during World War I.
After the war, new houses were built. In 1932, a new church of St. John the Baptist was built above the road.
Today, there is not a single trace that would testify to the importance of the village in the past.