New dating from a small cave on Croatia's Adriatic coast has pushed back the known human presence in the Dalmatia region by roughly 30,000 years, placing early toolmakers there during the depths of the last ice age and producing the oldest radiometric dates ever recorded at an archaeological site in the area.
The discovery comes from Mujina pećina, a cave in southern Croatia, where researchers applied a technique called optically stimulated luminescence, or OSL, to sediment layers packed with stone tools. The study, published in the journal Antiquity on July 22, 2026, was led by Ivor Karavanić of the Department of Archaeology at the University of Zagreb, working with colleagues from the Croatian Geological Survey, the University of Pisa, Eastern Oregon University, and Illinois State University.
A cave above the Adriatic
Mujina pećina sits north of the towns of Trogir and Kaštela, roughly 280 meters above sea level, a modest chamber measuring about 10 by 8 meters. Its floor holds layers of sediment dense with stone tools of the Mousterian tradition, a Middle Palaeolithic toolmaking style associated with Neanderthals and their contemporaries. The site holds particular importance for the region, since it is the first place in Dalmatia to be systematically excavated and radiometrically dated with a clear, unambiguous Middle Palaeolithic sequence.
Earlier work using radiocarbon dating and electron spin resonance had placed the cave’s occupation between roughly 49,000 and 39,000 years ago. Those methods, however, had a built-in limit, they could not reach far enough back in time to date the deepest layers of the deposit, where some samples fell beyond the range radiocarbon can measure at all.
How luminescence reads the dark
To break through that ceiling, the team turned to OSL, a method that dates sediment rather than organic material. The technique measures how long buried mineral grains, in this case quartz, have been shielded from sunlight, since natural radiation in the surrounding soil steadily builds up a trapped energy signal in the grains that is wiped clean by light exposure and begins accumulating again the moment they are buried. Reading that signal reveals how long ago the sediment was last exposed to daylight.
Because light exposure would corrupt the reading, sampling demands unusual care. In 2020, the researchers cleaned the cave’s stratigraphic profile, then drove opaque tubes into three separate layers, one near the top of the sequence and two near the bottom, so the sediment inside was never struck by light. The samples were sent to the Luminescence Dating Laboratory in Gliwice, Poland, for analysis.
Two layers far older than expected
The results split neatly in two. The uppermost sampled layer returned an age of roughly 35,000 to 39,000 years, closely matching the earlier radiocarbon estimates and confirming the existing chronology for that part of the sequence.
The two deeper layers told a startlingly different story. One came back at roughly 65,000 to 73,000 years old, and the deepest at between 73,000 and 82,000 years, about 30,000 years older than researchers had assumed for that part of the site. Rather than belonging to the Middle Palaeolithic phase known as Marine Isotope Stage 3, as previously thought, those layers instead date to the colder MIS 4, and in the case of the oldest, the earlier MIS 5a, deep within the last glacial cycle.
A wider pattern along the Adriatic
The oldest layer carries a further clue about who was making tools there. It contains a high proportion of transverse scrapers, a signature of the toolmaking tradition known as the Balkan Charentian, which gives archaeologists a sharper reference point for tracing how these early industries spread along the Adriatic coast and comparing them against finds elsewhere.
The new dates do not stand alone. They align closely with as-yet-unpublished OSL results from another Dalmatian site, Velika pećina in Kličevica, and come near the oldest dates obtained for Crvena stijena in neighboring Montenegro, together pointing to a broader pattern of early human settlement across the eastern Adriatic during this period. Scattered surface finds had long hinted at an even deeper human antiquity in Dalmatia, though those claims have never been firmly dated and remain unproven. What Mujina pećina now provides, for the first time, is solid radiometric evidence confirming just how far back human activity in this corner of the Adriatic genuinely reaches.
The researchers are appropriately measured about one detail. The uppermost sample sat at a shallow depth of just 170 millimeters, which means some contamination by later sediment cannot be entirely ruled out for that layer. The deep dates driving the headline finding, however, come from securely buried layers well down in the sequence, and it is those, around 70,000 and 80,000 years old, that rewrite the timeline of when people first lived along this stretch of the Croatian coast.
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Sources: Karavanić, I., Miko, S., Banda, M., Boschian, G., Becker, R., and Smith, F.H. (2026). “Mousterian Occupations in Dalmatia, Croatia, Early Dates Suggested by Optically Stimulated Luminescence.” Antiquity, 1 to 7. doi.org/10.15184/aqy.2026.10400