Asseria is located between Bukovica and the area of Ravni Kotari, 6 km east of Benkovci, and 1 km south of the village of Podgrađe. It was inhabited already in the pre-Roman period. In Antiquity, Asseria developed into a significant Liburnian town, which soon grew into a municipium. The city reached the height of its prosperity in the 1st and 2nd centuries AD. Asseria is mentioned by several ancient sources: Ptolmeus (Naturalis Historia, 3. 130, 139), Ptolmeus (Geographia, 2, 16, 6) and Ravennatis Anonymi (Cosmographia, 4, 16). The third season of systematic excavations undertaken in 2000 represents a continuation of the research conducted on the NW section of city walls and at the eastern gateway. New probes were opened in the urban tissue, at the very entrance to the hillfort. In front of the NW section of the city walls, a line of Antique wall was found, running alongside Late Republican monumental city walls. Also found was a Late Antique tower. Two horizons of Late Antique burials were uncovered in the space between the Late Antique wall and Late Republican city walls. The latter was built around the mid-first century BC. The Late Antique tower and early horizon of Late Antique burials can be dated to the second half of the 5th century, and the Late Antique citywalls to the end of 6th century. (Marko Sinobad)

In 2001, the excavations were continued on three locations: the city wall between the “western” and “Trajan`s” gateway, north of “Trajan`s” gateway, and on the location of the gateway on the NE section of the citywall. Two burials from the second phase of the Late Antique necropolis were uncovered between the “western” and “Trajan`s” gateways. Several Antique spolia were used in the construction of the inner facing of the Late Antique wall. During the excavations of the city walls north of “Trajan`s” gateway, Late Antique buttresses - a reinforcement of the Late Republican city walls - were found. Buttresses stand at regular intervals between the second and third, and the third and fourth Late Republican towers. Along that stretch of the wall, two phases of Late Antique burials were identified. Features of the urban tissue were found near the gateway on the NE section of the city wall. Several rooms were investigated, and three building phases identified. (Marko Sinobad)

This season of archaeological excavations was conducted in the section north of the western entrance to the town, at the area of the western entrance, then at the area between the Late Antique tower and “Trajan`s” gateway, and on the stretch of land between “Trajan`s” gateway and a Late Antique buttress leaning against the city wall. At the area of the western entrance to the town - possibly of pre-Roman origin - two distinctive horizons were identified. The former is contemporary with the foundations of the Late Republican city walls, while the latter belongs to the period following the construction of “Trajan`s” gateway – certainly not before the beginning of the 2nd century when “Trajan`s” gateway became the main entrance to the town. A double door similar to propugnaculum was also found. In the deepest layer, extending between the Late Republican city walls and Late Antique wall, a Liburnian gave was found. It was built of stone, on the Hellenistic model. Seven Early La Tène fibulae found in the grave and dated to 4th - 3rd centuries BC belong to Va phase of the Iron Age Liburnian culture. Six Liburnian tombstones were used for the construction of the inner facing of the Late Antique wall. At the area marked by the first Late Republican tower, “Trajan`s” gateway and the first Late Antique buttress, a thick layer of burning was identified, with numerous fragments of Roman ceramics and glass. A grave vault was found near the northern section of the city walls. The first out of five buttresses, between the second and third tower, was built on the grave dating to the Early Christian period (5th or early 6th century), which, therefore, determines a terminus ante quem non for the construction of the buttresses. (Marko Sinobad)

The new campaign of archaeological excavations was concentrated on the continuation of works at the position of the western entrance to Asseria, marked by the first Late Republican tower and “Trajan`s” gateway, then around the vaulted grave, and in the eastern part of the town near the gateway. At the western entrance to the town, on the front outer side of the propugnaculum, a corner stone with a large circular groove for the axis of the door was uncovered. On the inner side of the propugnaculum, a fragment of massive threshold, preserved in full width, was found. Under the threshold, an older road with kerb-stones was identified. The road is level with the first corner stone of the Late Republican city wall. Between the Late Republican city wall and Late Antique wall, on the line stretching between the first Late Republican tower and “Trajan`s” gateway, a segment of an Iron Age bulwark was uncovered. The wall was built of smaller and larger stone ashlars without the use of mortar. The outer facing of the wall was preserved, while the inner was destroyed by the construction of the Late Republican city walls. Under the northern section of the wall, a massive substructure was identified. In the rampart towards the city wall, three Liburnian funerary monuments were found. (Marko Sinobad)

In 2004 the excavations were continued in several places. The investigations included the area of the western entrance to Asseria, from the Late Antique wall towards the propugnaculum and the forum, then the area NE of “Trajan`s” gateway, in front of the northern section of the Late Republican city walls, and in the eastern part of the city by the gateway. Three graves were found close to the northern section of the city walls and the Late Antique vaulted grave. The first grave was built of spolia and dressed stone blocks, and covered with stone slabs. It can be dated to the end of the 5th or beginning of the 6th century. The other two burials date to the end of the 4th century and the 5th century. One of them was roofed with tegulae, and the other was a child burial in amphora. No grave offerings were found. In the eastern part of the city, in the immediate vicinity of the gateway, the excavations of service buildings were continued. Numerous fragments of pottery, remains of frescoes and mosaic tesserae were found. The outer facing of the wall was preserved up to the height of more than two meters. (Marko Sinobad)

During 2005, systematic excavation of Asseria continued, focusing on the eastern part of the city, at the newly opened city gate. Excavations continued in the area of the western entrance to Asseria, i.e. to the late Roman propugnaculum, in the direction of the forum, and inside and outside the late Roman wall. Excavation continued also from "Trajan's Gate" to the northeast, to the area in front of the northern part of the late Republican / early Imperial rampart, from the Republican second tower to the fifth late Roman buttress. At the western entrance to the city, in addition to the two construction horizons identified so far (late Republican/early Imperial and late Roman), the presumed pre-Roman hillfort gate has been identified. The excavation was made in front of the southern rampart at the western entrance, where the rampart takes the form of a sloping tower on which the double doors lean, and in front of the late Roman wall which closed the western entrance in the late 5th or 6th century. The edge blocks of the pre-Roman entrance to Asseria were identified, i.e. the entire width of the path that climbed along the southern rampart to the hill fort. Remains of clay as a binder were observed in some places in the structure of those irregularly carved blocks, otherwise the wall was built in the drywall technique. Remains of such Liburnian construction have already been determined in the area excavated from the first late Republican tower to "Trajan's Gate", i.e. in the space between the late Republican (early Imperial) rampart and the late Roman wall parallel to the rampart. The late Roman wall, right in front of the western entrance, was thickened in order to better protect the western city gates. Research under the northern ramparts, where a vaulted late Roman tomb and skeletal burials from late 5th and 6th centuries were discovered in previous years, resulted in improved knowledge about the late Roman wall which was better built in front of the north-eastern rampart, while further north where it follows the late Republican rampart, there is almost no binding. Larger stone blocks, fragments of sepulchral and urban architecture, as well as tombstones are literally piled up to form an embankment, i.e. a barrier protecting the main defensive wall, which was probably not well maintained at that time and damaged in places. In the structure of this late Roman defensive embankment, along with fragments of pillars architectural remains, three Liburnian tombstones have been found. One is fragmentary and its inscription has not been preserved. The other two are mostly preserved and rather typical tombstones for the area of Asseria. Late Roman tombs have been found also in the space between the earlier rampart and the late Roman embankment. Those are vaulted burials made of carved stones and spolia, as well as one child burial in an amphora and a grave lined with stone slabs and tegulae where a child had been buried with his dog. Part of the team worked on excavating and documenting the eastern part of the city, i.e. the area within the newly discovered city gates. Besides artefacts - coins, brooches and pottery shards - a floor with some remains of mosaics was discovered. After the conservation of metal objects and ceramic finds, the layers of the investigated buildings in the eastern part of the city will be dated more precisely (I. Fadić 2006, Hrvatski arheološki godišnjak 2/2005, 297–298).