In 1961 in Monastero, a hamlet of the municipality of Aquileia, a two storey building, part of the ancient Benedictine complex suppressed in 1782 by Giuseppe II, was designated as museum host.

The museum building is peculiar due to the presence on the lower floor of the remains of a paleo-Christian basilica with an elongated rectangular plan and an inscribed polygonal apse in a rectangular room.

Currently at the museum, one can admire lapidary materials such as sculptures, epigraphs and mosaics, originating from places of worship and from the necropolises of Aquileia, chronologically placeable between the fourth and tenth centuries. Looking out from the higher floors, the majesty of the paleo-Christian basilica can be observed. 

The first floor is nearly completely occupied by the mosaics of the basilica discovered in Beligna, a place name which alludes to the earlier existence of a sanctuary dedicated to Beleno. The building was composed of three elements, not necessarily coeval; naves, two wings, and an apse, the mosaic of which shows amongst schematically rendered vines, twelve lambs and a peacock, which are allusive to Christ and the Apostles. The mosaic dates to the end of the fourth century, and seems to belong to the first phase of the basilica.

Finally, worth pointing out is a relief with two uncompleted busts of the saints Pietro and Paolo, which seems to date back to the first decades of the fourth century.