The archaeological site of Fondo Cossar includes two or three dwellings, formerly excavated in the 1950s and again from 2009 to 2015 by the University of Padua. Neighbouring the south-eastern corner of the Republican city walls, this site belongs to one of the southern districts of Roman Aquileia, bounded by a road running north-to-south, whose paving stones are visible today, and by a parallel road to the west.
The houses feature scraps of walls and floors from different epochs, and namely from the 1st to the 4th centuries AD. Several mosaic floors from the late 1st century BC or the early 1st century AD can be seen in the southern stretch of the plot. The middle portion of the site is occupied by one residential unit. To the north, some ruins of walls and mosaic floors may be referred to a third dwelling.
Recent excavations helped identify in the central portion of the archaeological site the vestiges of one large house, which developed transversely between the two roads. Built in the early 1st century AD, the structure was arranged around a large open space, bounded by a mosaic-paved ambulatory and provided with a fountain to the eastern side. This garden area was faced by the main hall of the house, featuring a simple mosaic pattern on a white background, subsequently refurbished on several occasions over time. To the east, adjoining the road, some shops have been identified; to the west, another open area may have been faced by several rooms of the most private portion of the house. The recent discovery of an inscribed weigh allowed identifying the possible owner, one Titus Macrus.
- Mosaic of the Good Shepherd in unusual costume
A mosaic depicting the “Good Shepherd in unusual costume” was found in a huge representation hall and on top of an earlier mosaic floor of the same size. Inside a set of framing arches, the Good Shepherd with a typical crook and sheep behind him stands inside a circle, which is in turn inscribed into a larger one. The space between the two circles is filled with vine shoots, pheasants and peacocks. The allegories of the Four Seasons appear at the corners between the larger circle and the square frame around it. The mosaic features some typical themes of the arts in the 4th century, and may not be necessarily inspired by Christianity. Hence, it is now considered unlikely that the hall was used as a Christian oratory.
- Fishing scenes Another mosaic depicting a fishing scene and lying on top of at least two earlier mosaic floors adorned a large representation hall in the domus lying at the centre of the archaeological site. Inside a central square inscribing a circle, a small boat with fishing putti and four heads between dolphins at the four corners can be seen. The remaining surface is divided into squares with animals (including two tigers), but is now badly damaged. In this case too, the theme is too general and commonly found in both Christian and pagan mosaics from the 4th century to infer that the room was used as an oratory. Therefore, it is thought to be simply a reception hall in a rich house.