For thousands of years, the rugged limestone highlands of Slovenia’s Karst Plateau have kept a stunning secret buried beneath forests and rocky sinkholes.
Now, new research has revealed that this landscape once hosted massive, purpose-built stone megastructures that appear to have guided and trapped wild herds in one of Europe’s earliest examples of large-scale communal hunting.
This discovery not only sheds light on prehistoric hunting practices but also challenges our understanding of early European societies and their capabilities.
The discovery, led by archaeologists from the University of Ljubljana, was recently published in Proceedings of the National Academy of Sciences (PNAS). Using airborne laser scanning (ALS), researchers identified four monumental dry-stone “megastructures” spanning over 15 miles (25 km) of the Adriatic hinterland. This revealed an unprecedented glimpse into the ingenuity and cooperation of prehistoric societies in southern Europe.
“Monumental dry-stone structures identified on the Karst Plateau of the Adriatic hinterland through airborne laser scanning represent a previously undocumented form of large-scale hunting infrastructure in Europe,” the researchers write. “Their scale and strategic landscape integration imply coordinated communal effort, planning, and knowledge of animal behavior.”
The Karst Plateau — a limestone expanse stretching across the border of Slovenia and Italy — is famous for its sinkholes, caves, and dolines. It’s a challenging environment for farmers, but ideal for preserving stone features.
When the researchers mapped roughly 335 square miles (870 km) using ALS imagery, they unexpectedly discovered four vast funnel-shaped systems of low stone walls converging into deep, concealed enclosures.
Each installation consists of parallel stone alignments extending hundreds of feet to over 2 miles, leading into pit-like traps set beneath natural drops such as cliffs or rock ledges. These walls, typically about 1.5 to 3 feet high, weave through saddles, slopes, and dry valleys, topography that would have subtly funneled animal movement.
In plan view, the layouts resemble enormous “V” or funnel shapes, echoing the desert kites found across the arid landscapes of Southwest Asia and North Africa. These monumental stone traps were used to capture gazelles and other herd animals during communal hunts thousands of years ago.
Until now, no comparable “hunting kites” had been found in temperate Europe.
The largest of the four sites, labeled K01, is the most intricate. Its branching walls span over 2.2 miles and incorporate multiple side funnels and enclosures. The team estimates it was built using roughly 106,000 cubic feet of stone — the equivalent of nearly 1,000 dump-truck loads of rock.
Based on experimental construction rates, the researchers estimate the project would have required more than 5,000 hours of labor to complete. Such an undertaking reflects remarkable planning, coordination, and leadership — evidence of an organized, competent community working together toward a common goal.
“Even with 40 participants working two hours a day, construction would take nearly two months of coordinated effort,” researchers write. “The caloric demands alone, estimated at 300 to 500 kcal per hour of heavy stone moving, would require substantial provisioning, further reinforcing the communal nature of the undertaking.”
The architecture of these Karst megastructures suggests a level of behavioral insight and environmental knowledge rarely associated with early European foragers. Visibility modeling using GIS revealed that the stone walls were designed to manipulate what animals, and perhaps hunters, could see.
From a distance, the walls would have appeared as faint lines across open hills. But as animals moved between them, their vision would have narrowed toward the converging corridor. The final enclosure remained hidden entirely until the last 60 feet, where a sudden drop beneath a cliff created a dead end. The prey, likely red deer or wild boar, would have been driven forward by coordinated hunters until it was too late to escape.
The stone megastructures’ design, the authors argue, aligns perfectly with the logic of communal hunting, not herding. “These confined endpoints, positioned beneath abrupt rock drops, offer no clear exit and would have posed significant hazards for mobile prey,” researchers write. “The structures’ overall design is difficult to reconcile with herding practices and instead points to a purpose-built logic of interception.”
To determine the structures’ age, the team excavated a trench within one of K01’s enclosures, uncovering a thin buried soil horizon containing oak charcoal, burnt clay, and a flint bladelet. Radiocarbon dating placed these materials between 3500 and 1700 years before present, corresponding to the Late Bronze Age through the Roman period. However, crucially, this layer formed after the site’s abandonment.
Paleoenvironmental data indicate that by around 4000 and 2000 years ago, the Karst region was reforesting rapidly, suggesting the traps were built during an earlier, more open landscape, possibly during the Mesolithic, around 10,000 years ago, when wild red deer dominated the area’s ecology.
At nearby cave sites such as Grotta dell’Edera and Pupićina Cave, red deer bones make up over 90 percent of animal remains from that period, showing clear evidence of intensive, seasonal hunting. Archaeologists believe these hunts may have been accompanied by large communal gatherings, events that blended subsistence, ceremony, and social bonding.
If confirmed as prehistoric hunting systems, the Karst installations would be the westernmost examples of an ancient technology once thought limited to the deserts of Arabia and North Africa.
However, beyond their function, the megastructures tell a deeper story about human cooperation. Their construction required shared planning, sustained effort, and intimate knowledge of animal behavior, all hallmarks of organized social life well before agriculture transformed Europe.
Moreover, the discovery challenges long-held assumptions that Europe’s hunter-gatherers lived in small, isolated groups. Instead, these stone megastructures hint at societies with collective planning, territorial organization, and a shared ability to reshape the land, not unlike the builders of megaliths or early city walls.
Ultimately, researchers suggest these walls of stone don’t just represent how ancient humans caught their prey, but also how they bound their communities through labor, shared purpose, and an understanding of the land that shaped their lives for millennia.
“These installations expose critical dimensions of prehistoric life,” researchers write. “[They reveal] the coordination of communal labor beyond the domestic sphere, the transformation of landscapes into infrastructural systems, and the coupling of animal ecology with architectural foresight.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com