The decumanus of Aratria Galla, currently visible from Via Giulia Augusta, the entrance road to Aquileia that cross the Forum and follows the trend of the cardus maximus of the Roman city, was discovered in the 70s for a stretch of about one hundred meters.

From east to west it connected the river port with the Forum and the theater: the civilian basilica overlooked it and you can see the remains in the archaeological area recently acquired by the Aquileia Foundation. The roadway, still intact, was made of trachyte, a volcanic rock from the Euganean hills. According to two twin inscriptions, referred to this street by some scholars, the paving was an act of munificence of a woman, Aratria Galla, hence the name conventionally assigned to the decumanus.

When the "zigzag" walls, dating back to the 6th century, were built, the decumanus remined in use, although outside the city walls.