The research of the Glac site in 2017 brought significant discoveries indicating this building complex is not only large, spreading over a few hectares, but was built with luxurious materials and hence belonged to an extremely wealthy owner. With this knowledge, the Glac Project team continued to explore locations where the most interesting scientific questions emerged.
One of the essential archaeological procedures that allow researchers to understand the history of a site from its origins to the present times is to examine plans and maps that have evolved through history. Nowadays, special computer applications allow all maps and plans to be consolidated, positioned and analyzed using the integrated geographic information systems (GIS). Therefore, a GIS database for Glac Project was created where all the data related to space are entered.
With the help of colleagues from the Archive, Museum of Srem and „Blago Sirmijuma" (The Treasures of Sirmium) publishing house from Sremska Mitrovica, cadastral plans of the Glac site area originating in the 19th century were obtained. They show the location where the estate of Peter Glac (Glatz) was built and the exact locations where the house, road and vineyard were situated. Therefore, new trenches were placed in the northern part of the site where the analysis of historical maps and geomagnetic survey indicate the Glac's estate was located. There were immediate results. A road leading to the estate and a fence wall were discovered. Interestingly, it was established that the luxurious materials originating from the ancient villa were used in the construction of this wall. Apart from the 19th-century brick, luxurious pieces of marble slabs originating from Tunisia and Asia Minor were built in the wall.
Special attention was paid to the area in which the settlement from late antiquity was noted. The most significant structure from this period is the circular furnace. The way it was built is intriguing. At the time of its construction, the roof and the walls of the room in which it had been constructed were already destroyed. A space near the northern wall was defined, where a few large bricks were buried circularly in the destruction layer, and several layers of clay, pebble stone and bricks were set intermittently. In this way insulation was ensured, preventing the dissipation of heat inside the furnace.
There was a significant discovery close to this area. Coins were found, underneath a mortar floor, revealing the period after which the floor was created, and thus the building too. Since this coin is dated to the end of the third century, it can be concluded that the floor originates from the same time. The coins were found in a distinct layer in which traces of baked mud and garrison were discovered, which could indicate that there was a hut or some other structure, made of wood and mud, that burned down in a fire.
Pieces of ceramic vessels, characteristic for earlier periods, were found on several places on site. However, a find from a trench near the mosaic room is definite proof that the assumption could be made of the existence of a settlement before the luxurious villa from the period of Tetrarchy on the site. It is a special kind of jewelry - fibula. Fibulas are Roman decorative needle pins used to tie the clothes on the shoulder. Roman women often wore a pair of two fibulas that tied the upper part of their dresses onto their shoulders. Men, on the other hand, tied their robes with fibulas on their right shoulder. By its form, the fibula that was discovered next to the mosaic can be precisely dated to the end of the first century, which is the time of origin of the fragments of special, luxurious drinking vessels.
The discovery of the mosaic position in one of the rooms last year presented the Glac researchers with a challenging task to examine the purpose of this room, as well as the reason why the mosaic is precisely there. However, the answers to these questions are not easy to provide. The surface of 30 square meters discovered in 2017 has increased to over 220 square meters, found in 2018. Based on this year's discovery of two walls it is known that the room was 15 meters wide. The length of the room remains unknown since the fourth, northwest wall, of the mosaic room, was not discovered. What we know for the time being is that the length of the room exceeds 15 meters.
Equally significant results were achieved in the western part of the site this year. A discovery of a solid limestone mortar floor in a small trench last year demanded a more comprehensive further research. The walls of a more massive structure, revealing its monumentality and quality of construction, were discovered. The foundation zone of one of the walls, over a meter wide, was built of bricks immersed in lime mortar and is of strength equal to that of concrete. Based on these finds, it can be assumed that the structure was considerably high and judging by the direction of these walls which are parallel to the walls in the southeastern part of the site, it can be concluded that they belong to the same construction concept of a vast complex from the period of Tetrarchy.
In addition to this discovery, another one has brought new data supporting the significance of the Glac site. The traces of a narrow, curved ditch were revealed in the mosaic room, expanding to the west and east of the archaeological trenches. The discovery of WWI rifle bullets helped solve the enigma of the purpose of this ditch. It has previously been known that there are Austro-Hungarian soldiers' ditches from 1915, at Glac, dating from the Battle of Leget. The first ever data on the mosaic findings were recorded in the military report of February 1915. By comparing the military plans of the Vienna War Archives, where the positions of ditches, cannon stations and minefields were accurately marked, and the Glac site plan, it was concluded that this winding ditch is in fact the trench from 1915.