The Slanje, Stari Gradec hillfort spans 12.5 hectares and is encircled by ramparts up to 14 meters high. Together with sites in Jalžabet and Martijanec, it forms a rare archaeological landscape from the Early Iron Age.
On the northern slopes of Kalnik, hidden beneath layers of soil and vegetation, lies a prehistoric fortress whose dimensions surpass even some of Croatia's most renowned medieval strongholds. The site of Gradina Slanje, Stari Gradec, located in Varaždin County between Vinogradi Ludbreški and Slanje, covers approximately 12.5 hectares and is surrounded by massive earthen ramparts that reach up to 14 meters in height in some sections.
Lead researcher Dr. Saša Kovačević from the Institute of Archaeology, who heads the excavations in Slanje, Martijanec, and Jalžabet, described his initial impressions from the field. "When we first came here, even our fellow archaeologists couldn't believe this site was of such magnitude," Kovačević told Večernji list.
To convey the monumentality of the discovery, Kovačević offers concrete comparisons. The area of the hillfort is almost equal to that of Knin Fortress, while Grebengrad, one of the largest medieval fortifications in northwestern Croatia, covers only about half a hectare. "These figures alone speak volumes about the monumentality of this site," he emphasizes.
In the immediate vicinity of the hillfort, there is also a cemetery with burial mounds from the Early Iron Age, which currently presents a major enigma for archaeologists. Slanje is not an isolated site but part of a broader cultural area that includes highly significant locations in Jalžabet and Martijanec.
Jalžabet, located 15 kilometers southeast of Varaždin, is one of the most important Early Iron Age landscapes in Croatia. The local tumulus known as Gomila, 65 meters wide and eight meters high, is a funerary monument of the eastern Hallstatt culture circle from the 6th century BC. Archaeological research there began as early as the 1960s and intensified from 2016 onward.
Among the finds are decorated arrowheads made of bone and antler, remains of a scale armor of the eastern type made of iron and bronze, amber jewelry, and ceramic and bronze vessels. The artifacts unearthed at this site point to the influence, power, and wealth of the ruling class of the eastern Hallstatt culture. The Jalžabet ruler was the last in a line of chieftains who held sway over this area, after which their society collapsed and their civilization vanished.
In the autumn of 2017, the Gomila tumulus was looted and severely damaged, prompting rescue archaeological excavations funded by the Ministry of Culture. According to Kovačević, the monumental funerary architecture and complex burial rituals confirm that Gomila is one of the most important prehistoric monuments of its kind excavated in Europe in recent times.
Numerous luxury items made of bronze, iron, bone, and wood were deformed to varying degrees or completely destroyed, but some finds were not exposed to fire, indicating complex rituals performed at the site.
In addition to Slanje and Jalžabet, research is also underway on a tumulus two kilometers south of Donji Martijanec. This burial mound from the Early Iron Age is about 80 meters wide and roughly 15 meters high, dating from between the 8th and 5th centuries BC.
Dr. Kovačević has been leading systematic archaeological research in Varaždin County for nearly a decade. After beginning in 2016 at the tomb of the eastern Hallstatt ruler in Jalžabet, the work continued in Martijanec and then in Slanje.
Varaždin County officials emphasize that Slanje, Martijanec, and Jalžabet together form an archaeological landscape whose concentration of monumental sites is rarely encountered, and its research, protection, and presentation open a new dimension of cultural and tourism development.
"Our work does not end with the archaeological excavation itself. From the very beginning, we have been thinking about the protection of the site, its preservation, and its future presentation to the public, so that its value is preserved in the long term and brought closer to people," Kovačević concludes.
In the continuation of the research, the goal is to determine the time of construction of the Gradina hillfort, how it was used, and the identity of the people who controlled it. There are still many unresolved questions about the history of this region that archaeology will have to answer.
