The territory of Aquileia can be described following the course of the Natissa, the resurgence river that surrounds the city.
The story begins by the Roncs, a territory today in the municipality of Terzo di Aquileia. The water came to the surface through the springs (boiòns), whose remains are still visible. Today the Natissa starts well beyond the Roncs, but it is a relatively recent situation, due to reclamation works. However, looking at the old prints, one can see that once the Natissa originated in this location, in the middle of a forest that was deforested at the beginning of the nineteenth century with the purpose of intensive cultivation. The woods and waters were in fact a problem, which was then resolved with the complete deforestation of the area and a land reclamation that also altered the various ditches and canals. This location is still the crossing place of several streams, like the Aussèt and the Marignùl, the ancient Malignum flumen.
After the Roncs, the Natissa crosses the Paludèi , a low area, rich in archaeological remains from the Roman period, to arrive at the village of Monastero, the site of an ancient female cloistered convent, suppressed in 1782 by Emperor Joseph II of Austria.
Beyond the village, the Natissa approaches the Roman wharf and, at the height of the basilica, meets with another irrigation canal of Aquileia (the Roggia del Mulino di Monastero) heading westward and going inside the village, passing under the San Felice arch, a remnant of the medieval walls. The stream then passes under two bridges: the one on the current state road to Grado, called Punt dal Crist and the one in Piazza Garibaldi, in front of the Town Hall, called Punt di Plassa.
Once outside the perimeter of the ancient city, the Natissa arrives at Durìda, where it receives the waters of the Fiume di Terzo, which in turn pass under the current Ponte delle Vergini. Here, the waters now mixed with salty seawater, head south lapping the lands of the Malburga on the eastern side and the Marassìn on the opposite side.
Along this stretch of the river, just after the large dock, are the remains of reclamation culverts from the eighteenth century: at this point the sea is not far and it would be quite a trouble if there were no levees along the river and the sea: the level of this land is in fact under the sea.
The Natissa runs along the Panigai on the right and the Montonus on the left; then flows into the lagoon. From here, at a short distance, one can see the pine forest of S. Marco, which for centuries has hosted a small church, built in memory of the Aquileia legend according to which Apostle Mark, coming from Alexandria, Egypt, disembarked right here to bring the Good News to Aquileia, the Roman city capital of the Tenth region Venetia et Histria.