The Concordiese National Museum was opened to the public on 28 October 1888. Its collection consists almost exclusively of materials from the colony of Iulia Concordia, found by chance by stone quarrymen, during regular archaeological excavations or as donations from local families (including the Muschietti family).
In 1873, the first significant discovery was made east of Concordia. It was the lawyer Dario Bertolini who realised its importance and promoted the expansion of the excavations: an entire late antique necropolis emerged from the earth, later named the “Militi burial ground” due to the large number of inscriptions dedicated to soldiers. This was the beginning of a long period of research and excavations that led to the drafting of the first map of the colony. At Bertolini's request, the Municipality of Portogruaro acquired a plot of land owned by the Episcopal Seminary and in 1885 the first stone of the future Concordiese National Museum was laid.
The museum building is shaped like a Christian basilica with three naves. Its architecture evokes the early Christian era in Concordia. The atrium contains a 14th-century sculpture of the Madonna and Child Enthroned, carved from a fragment of a Roman inscription, and a fragment of a relief depicting three lictors in procession. The large hall contains statues, mosaics, architectural elements, funerary steles, portraits and a wealth of epigraphic material from the city of Concordia and its monuments. In an adjoining room, to the right of the entrance, there are marble portraits, decorative elements from public and private spaces in Concordia and coins found in the Concordia countryside.
On the upper floor, in room 3, a number of display cases contain finds from local collectors' collections or from excavations carried out at the end of the 19th century by Dario Bertolini. These are artefacts relating to the pre-Roman occupation of the site and the Roman city, including some figurative bronzes. The exhibition continues with smaller items divided into categories: gems, amber ornaments, oil lamps, other everyday objects and glassware, including the famous engraved cup depicting Daniel among the lions. In Room 5, there is a selection of artefacts found in more recent excavations in Concordia.
