The Roman Forum of Trieste is the open-air archaeological area on top of San Giusto hill, between the Cathedral of San Giusto and the castle. This was the civic centre of Roman Tergeste: a large three-aisled basilica where courts sat and merchants did business, and beside it a paved square that was probably the forum. Today a row of columns on the old stone base marks the spot, with wide views over the city and the gulf.
The Roman Forum at a glance
- Where: on top of San Giusto hill, next to the Cathedral of San Giusto and below the walls of the castle.
- Built: the civic basilica and the monumental entrance to the sacred area date from the second half of the 1st century AD.
- Excavated: in 1929–1934, when the basilica and a paved area with traces of stalls came to light.
- What it is today: an open-air archaeological area with columns and foundations of the basilica, part of the city's archaeological itinerary.
- Time needed: 15–20 minutes, more if you also visit the cathedral and the castle.
From Tergeste's civic centre to a hilltop ruin
Long before the Romans, San Giusto hill held a prehistoric hill fort, a castelliere. Under Rome the hilltop, protected by walls, became Tergeste's public and religious centre. In the second half of the 1st century AD a monumental entrance, the propylaeum, was built to a sacred enclosure that probably held a temple of the Capitoline Triad: Jupiter, Juno and Minerva. To its left rose the civic basilica, a three-aisled hall about 88 metres long and 23.5 metres wide, where justice was administered and business was done. On its sea side lay an open paved area that was probably the forum, or part of it.
In the Middle Ages a bishop's residence, a monastery and the church of St Sergius were built over the basilica, and much of its stone was reused in the first cathedral; none of these medieval buildings survives. The cathedral and the castle rose on either side. The Roman remains only came back to light in the excavations of 1929–1934. Digging still turns up surprises: during recent pipe works in the street below the cathedral, archaeologists found a late Roman storage pit and an inscribed stone block, probably from the propylaeum above.
What to look for
- The columns: a row of columns standing on the basilica's stone base in the middle of the area, some still with their capitals.
- The plan of the basilica: the foundations let you trace the long hall with its central nave and two aisles.
- The cathedral bell tower: parts of the Roman propylaeum are built into it, so look for ancient stonework in its lower part.
- The Monument to the Fallen: Attilio Selva's First World War memorial, inaugurated in 1935, with five male figures in a battle scene, at the end of the Parco della Rimembranza just before the square.
- The view: walk to the edge of the hilltop for a look over the rooftops of the old town to the Gulf of Trieste.
Tips for your visit
- Make a single visit of the hilltop: the forum, the cathedral and the castle all stand around the same square.
- The walk up from the old town is short but steep. One way up is the Scala dei Giganti, the great staircase that climbs from Piazza Goldoni.
- Late afternoon light is kind to the pale stone of the columns, and the hilltop is cooler then on summer days.
Nearby
- Cathedral of San Giusto: right beside the forum, formed in the 14th century by joining two older churches, with medieval mosaics in its apses.
- Castello di San Giusto: the castle next to the forum, begun in 1470 and completed in 1630. The Lapidario Tergestino in its Lalio bastion displays stones from the basilica, the forum and the propylaeum.
- Arco di Riccardo: a small Roman arch in the old town below, about seven metres high, usually thought to be a gate in the town walls of Augustus's time.
- Roman Theatre: the remains of Tergeste's theatre at the foot of the hill, on the edge of the old town.
See Trieste with World City Trail
Our Trieste scavenger hunt turns the city into a game you play on your phone. The route links 10 stops and takes around 2 hours, with about 46 minutes of walking. It takes you to places such as the Ponte Rosso on the Grand Canal and the Teatro Verdi, in the lower city below San Giusto.
If you prefer a different format, there is also a self-guided walking tour and an outdoor escape game in Trieste.
Play the Trieste scavenger hunt →
Take the self-guided walking tour of Trieste →
Play the outdoor escape game in Trieste →
Facts checked in October 2026.