Denmark's Radical Archaeology Experiment Is Paying Off in Gold and Knowledge

Scientific American

18 hours ago

Ole Ginnerup Schytz, an engineer in Denmark's sleepy Vindelev agricultural area, had used a metal detector only a handful of times when he found a bent clump of metal in a friend's barley field. He figured it was the lid from a container of tinned fish and tossed it in his junk bag with the other bits of farm trash that had set his metal detector beeping: rusty nails, screws, scrap iron. A few paces away he dug up another shiny circle. Someone had clearly enjoyed a lot of tinned fish here—into the sack it went. But when Ginnerup found a third metal round, he stopped to take a closer look. Wiping the mud from its surface, he suddenly found himself face-to-face with a Roman emperor. At that point he had to admit 'they weren't food cans,' Ginnerup recalls with a chuckle.
After a brief intermission for an online Teams meeting for work that December day in 2020, Ginnerup dug up 14 glittering gold disks—some as big as saucers—that archaeologists say were buried about 1,500 years ago, during a time of chaos after ash clouds from a distant volcanic eruption created a miniature ice age. Four medallions feature Roman emperors, and several bear intricate geometric patterns. But the real showstopper is an amulet called a bracteate with two stylized designs: a man in profile, his long hair pulled back in a braid, and a horse in full gallop. An expert in ancient runes says she was awestruck when she finally made out the inscription on top: 'He is Odin's man.'
These embossed runes are the oldest known written mention of Odin, the Norse god of war and ruler of Valhalla. Ginnerup's bracteate, which archaeologists describe as the most significant Danish find in centuries, extended the worship of Odin back 150 years—and it's all because Ginnerup received a metal detector as a birthday present from his father-in-law.
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Many other European countries have prohibited or heavily restricted hobbyist metal detecting, but Denmark has embraced it, creating a system for members of the public to hand over finds to government archaeologists. The result has been an embarrassment of riches, with more than 20,000 items turned in annually in recent years. The curators assigned to identify and catalog the artifacts can't dream of keeping up, but the fruits of their collective labor are clear: whereas neighboring countries have only vague sketches of the past, metal detectorists have filled in the ancient map of Denmark with temple complexes, trade routes and settlements that would have otherwise been lost to history.
'Private detectorists have rocketed Denmark ahead of its neighbors in archaeological research,' says Torben Trier Christiansen, curator of archaeology at Denmark's North Jutland Museums. 'There's nothing 'amateur' about them.'
Denmark has been inhabited since the end of the last ice age, when nomadic hunter-gatherers from southern Europe arrived following the migration of reindeer and retreating glaciers as early as 12,500 years ago. The ancestors of modern ethnic Danes showed up some 5,000 years ago, journeying from the steppes of what is now Ukraine and southwestern Russia. Their descendants lived in small farming communities across Scandinavia for thousands of years, building megaliths and barrows for their honored dead and making human sacrifices in bogs to appease their gods.
In the early centuries of the common era, these farming communities coalesced into a series of Germanic tribes—the Cimbri, the Teutons, the Jutes, the Angles and the Danes—who became skilled seafarers, explorers and metalworkers. Because precious metals—including silver, gold and the components of bronze—do not occur naturally in what is now Denmark, its denizens had to barter for or steal these metals from abroad. They traded extensively with the Roman Empire, which never reached as far north as Scandinavia.
By the ninth century, in the Age of the Vikings, Norsemen traded mainly in slivers of silver by weight, but they also had access to dirhams from the Islamic caliphates, solidi from the Roman Empire, and gold from the shores of Ireland, all of which have been found by their metal-detecting descendants. Denmark has been a unified kingdom since at least the 10th century, making it the oldest surviving monarchy in Europe.
Metal detectors hit the Danish consumer market in the late 1970s. 'Before that, metal detectors were really just military equipment' used to find unexploded ordnance from World War II, Trier explains. Through the 1980s, metal detectors were so uncommon that most European countries didn't have laws to govern who could look for relics and where. But that all changed after some high-profile thefts demonstrated how much damage a bad actor with a detector could do. The Swedish island of Gotland became something of a battleground between professional archaeologists and looters—both locals and 'tourists' from abroad—who used metal detectors to find and plunder Viking Age sites, making off with many silver relics. The episodes soured Sweden on private detectorists for decades, Trier says. And beyond outright theft, many archaeologists believed they were destroying important archaeological context in a selfish desire to hold history in their hands.
As Sweden drafted legislation to heavily restrict private metal detecting, one man decided Denmark already had a relevant law on the books—from 1241. Olaf Olsen, the director of the Danish National Museum in the 1980s, championed the idea that detection finds could fall under a medieval law that declared all precious metals without a clear owner the property of the crown.
Olsen's interpretation of the Danefæ ('Danish treasure trove') law led to one of the most permissive approaches to metal detecting in Europe. Today anyone can metal detect in Denmark without a permit as long as they have the landowner's permission and agree to turn over any potentially historic finds to the government. It's a classically Danish system built on social responsibility—in a country where people regularly leave babies to nap outside in their strollers, it's no wonder the government trusts the public with treasure.
It wasn't until about 10 years ago, though, that interest in metal detecting really surged, thanks to television shows and social media. In 2013 about 5,600 items were turned in for evaluation as potential Danefæ. By 2021 that number had skyrocketed to more than 30,000. That's a lot of nonarchaeologists digging holes. But in Trier's opinion, Danish archaeologists benefit from all these boots on the ground.
About 60 percent of Denmark's landmass is dedicated to farmland, and much of that is tilled every year. Modern plows can reach more than half a meter into the soil, bringing a fresh slate of long-buried objects close enough to the surface for a metal detector to spot them. 'But once an artifact is at the surface of a field, it's going to be facing frost and sun and rain and the climate,' Trier explains. Then it's a race against time before the object is destroyed.
Whatever is in Denmark's forests can safely wait another 200 years for professional archaeologists to get around to it, Trier says. But the detectorists walking plowed fields are the front lines of archaeological rescue operations.
A prime example is a discovery known as the Vaarst complex. A private detectorist surveying a farm in northern Jutland found a concentration of jewelry—gold rings, dress pins and cloak clasps—so substantial that Trier mounted a rescue dig to stabilize whatever archaeological context had managed to escape the plow. Over the next two years Trier and a team of professional archaeologists uncovered a vast burial complex with hundreds of graves, many including human remains, their heads all oriented west toward the North Sea. Farming and erosion had eaten away at the topsoil for so long that only a few centimeters of depth covered many of the graves. 'One or two more seasons of plowing and they would have been gone,' Trier says.
Just a kilometer away from the Vaarst complex is a modern town called Gudum. Historians had puzzled over the origin of the town's name, which translates to 'home of the gods.' Now, thanks to the detectorists' find, researchers believe it might have been the site of a major religious center.
It's a big ask to expect the finder of a pristine ancient treasure to turn it over to a government bureaucracy. Detectorists find ways to keep their favorite artifacts close to their hearts.
Detectorists hand over their artifacts to Denmark's 28 local archaeology museums—an astonishing number for a country one-third the size of New York State. It's up to local archaeologists such as Trier to designate sites of interest before they're destroyed by farming or construction and to identify and record the finds before they're passed on to the central Danefæ department at the National Museum. Trier says he has about 300 detectorists who regularly turn in finds to him. 'They can often tell even from a teeny sound the detector makes what kind of an object and how deep it is,' he notes.
Some private detectorists have résumés that rival those of professional archaeologists. On an uncharacteristically sunny day in March, husband-and-wife duo Kristen Nedergaard Dreiøe and Marie Aagaard Larsen picked me up at a train station in southern Denmark, in an area north of the border with Germany. 'You know, people used to call this place the 'rotten banana' of Denmark,' Aagaard told me. But not anymore. The detectorist power couple's finds have revealed that the area where Aagaard grew up was an important hub of wealth and power 1,000 years ago.
In 2016 Aagaard, Dreiøe and their friend the late Poul Nørgaard Pedersen discovered nearly 1.5 kilograms of Viking Age gold artifacts near the modern town of Fæsted, including armbands that archaeologists have interpreted as oath bands: twisted rings that would have been given by a chieftain or lord to his lieutenants to wear as a sign of their fealty. It's the largest hoard of Viking gold ever discovered in Denmark.
But Aagaard and Dreiøe haven't let the gold go to their heads in the decade since. Quite the opposite: they show an unusual willingness to investigate every signal on their detector, even for iron. Iron is a perennial pest for detectorists. It elicits a loud, petulant scream from the detector and is almost always farm trash. Once detectorists become experienced enough to recognize this sound, most won't lift a shovel for it.
Aagaard and Dreiøe's dogged digging, however, led them to discover a cache of more than 200 iron weapons—spears, lances, daggers and swords—in 2018. Subsequent excavations by the local archaeologist, Lars Grundvad, uncovered a series of temples used by what he calls a 'cult of destruction' starting around C.E. 0. They found evidence of at least 15 incarnations of the temple, each a few meters apart from the rest, spanning an estimated 550 years, Grundvad said. Many of the weapons seem to have been placed in support poles—whether as sacrificial offerings in the inauguration of a new temple or as a way of symbolically 'killing' the old one remains unclear. Fifteen temples 'felt very Indiana Jones,' Aagaard says. Looking back, Aagaard and Dreiøe laugh when they remember they considered taking up hunting or sailing as their joint hobby instead.
The dig site I visited with Aagard, Dreiøe and Grundvad in March is in a field where grain is typically grown, just a stone's throw from a highway. On the horizon we could make out a suburban neighborhood, windmills—and a dolmen, a burial mound with large stones perched atop it, probably about 5,000 years old. The dolmen was already ancient by the time of the Vikings, Grundvad mused.
The museum had rented a lime-green excavator for the occasion. A young tradesperson operating the digger painstakingly scraped layers of just a few centimeters of soil at a time from the surface of the ground over an area about the size of two basketball courts. Four metal detectorists, including Aagaard and Dreiøe, had taken the day off from work to participate. Supervised by a pair of local archaeologists, they followed behind the excavator as it crept through the plow layer toward what we hoped would be an undisturbed archaeological context.
Just 20 minutes in, Dreiøe let out a triumphant whoop. The archaeologists and detectorists all gathered to see a Roman silver coin called a denarius cradled in his palm. 'Today is like my birthday, New Year's and Christmas in one,' Aagaard said.
As the day wore on, about 10 more coins in bronze and silver, carefully labeled in individual baggies, accumulated in Grundvad's bucket of finds. But the archaeologist was more interested in a small, curved piece of bronze that Aagaard found: a fragment of a goblet or a pot the coins might have been buried in. The hope is that deep under the plow layer, there might be evidence of a settlement.
Grundvad treats Dreiøe and Aagaard—who are, by trade, a sales manager and a psychologist, respectively—as colleagues. 'At first we wondered if they'd roll their eyes at us because archaeology is their job and our weekend hobby,' Aagaard says. 'But not Lars. He's one of the youngest and hippest local archaeologists.'
Nearly every weekend during the detecting season, Aagaard and Dreiøe take their 'time machines' out in the field. They send snapshots of their discoveries to Grundvad for immediate identification. 'Not to sound arrogant about it, but we've gotten used to them bringing in extremely nice finds,' Grundvad said. In many ways, he credits Dreiøe, Aagaard and Nørgaard with putting his little museum on the map. It's a very different mentality than his colleagues in Sweden have, according to Grundvad. 'The Swedish authorities think that metal detectorists will destroy finds, take them out of their context. We think the finds are being saved.'
The oldest wing of the National Museum, in downtown Copenhagen, is home to Denmark's treasure bureaucrats. It's up to the curators of the Danefæ department to identify the thousands of objects streaming in from the fields every year and decide which are worthy of joining the museum's research collection—and which will earn their finders a monetary reward.
Even though detectorists can now upload photographs and GPS coordinates of their finds to a dedicated app, the curators' identification process remains much as it was 40 years ago. The best resources are thick reference books, their margins filled with hand-drawn diagrams and annotations from curators stretching back to the 1940s. With the breadth of objects that come across their desks, from flint-knapped stone tools and Bronze Age weapons to Viking jewelry, curators need an encyclopedic knowledge of Danish prehistory just to have a chance of knowing which book to reach for.
Kirstine Pommergaard knows what style of brooch was popular in C.E. 300. She can tell whether a coin is a Roman solidus or a dirham of the ancient Islamic caliphates at a glance. 'You have to love items and the stories they can tell to be able to do what we do,' she says.
Pommergaard is a curator of prehistoric archaeology and one of just three archaeologists in the country dedicated to identifying Danefæ full-time. As of 2025, there's a daunting backlog of more than 50,000 objects in a secret 'secure facility' awaiting evaluation. '[Each one is an] important piece of the puzzle, even if it's not made of gold or if we have 1,000 of them already,' she says. But what Pommergaard cherishes most are the items whose very existence reveals unforeseen connections.
All the curators were dazzled when a detectorist turned in a solid gold ring set with a blood-red garnet. But Pommergaard, a self-professed craftsmanship nerd, became fixated on something many might have overlooked in the quest to figure out the origin of the ornament: the underside of the ring's setting. Four delicate curlicues that the goldsmith used to attach the shank to the head were a smoking gun for Pommergaard. This jewelry-making technique was exclusive to Frankish craftsmen living under the Merovingian dynasty, a royal dynasty that used marriage diplomacy to consolidate power across central Europe after the fall of the Roman Empire. Thumb rings with a similar construction have been found in the graves of high-status Merovingian women on the level of empresses and queens, Pommergaard says.
Could the ring have been a spoil of war? The stone says otherwise. Although the Merovingian queens wore signet rings, red stones were a symbol of power among the Nordics. 'There must have been someone in Emmerlev who was important enough to marry one of their daughters off to,' Pommergaard says, referring to the hamlet nearest to where the ring was found. Before the discovery of the ring, Emmerlev was known only as the site of a cattle trade that operated in the 1500s.
Pommergaard had dreamed of working with ancient items since she was seven years old, when she found half of a stone ax with her grandfather on the Danish island of Fyn. But what she probably didn't foresee—and what seems to be her least favorite part of the job—is being asked to put a price on the priceless.
It falls to the Danefæ team to determine the finder's reward for each item chosen for the museum's collection. Most of the payouts are quite modest and far below what the objects might fetch on the black market—250 or 350 kroner (around $40 or $50) would be a typical finder's fee for a coin from the 12th or 13th century. But the blockbuster treasures can command eye-watering sums. Aagaard, Dreiøe and Nørgaard received just over a million kroner for the oath ring treasure, the equivalent of about $150,000. Ginnerup—the discoverer of the golden bracteate with Odin's name—declined to share how much he received for his hoard. 'The National Museum emphasizes not to talk about the money,' he says.
Pommergaard says she isn't allowed to discuss how they decide the payouts, only that they consider an artifact's historical value and condition and the care the finder took in collecting it. Altogether, Danish detectorists received the equivalent of $1.3 million in 2023, up from just $130,000 in 2012. Technically the sky's the limit—the law doesn't stipulate a cap on Danefæ payouts. But the same can't be said of the budget for archaeologists to process the finds.
Currently the average wait for an artifact to be processed by the Danefæ team is 'at least 2.5 years' once the object reaches their doors, according to Pommergaard, but that duration doesn't include the time the objects spend being evaluated at local museums, which don't receive dedicated funding for Danefæ. As local museums struggle to process the finds their detectorists turn in, they risk missing the opportunity to identify sites such as the Vaarst complex before they're lost to construction or the plow, Trier says.
The long processing time also means some prolific detectorists have tens of thousands of kroner in rewards tied up in the system, sometimes for up to a decade. But archaeologists and hobbyists agree that detectorists aren't in it for the money. 'Hour for hour, we'd be better off picking up cans off the side of the road and turning them in for the recycling fee,' says Troels Taylor, a longtime detectorist based in Zealand. Nevertheless, 'we are grateful for our system where we get a little reward for the huge work and effort we do,' Taylor adds. Detectorists do want to know their finds are being examined and used for research, however. If not, they'd be happy to display them in their homes.
It's a big ask to expect the finder of a pristine ancient treasure to turn it over to a government bureaucracy. Detectorists find ways to keep their favorite artifacts close to their hearts. Taylor, like many detectorists, has several tattooed on his body, including one image from a strap end he found of two stylized beasts that twist on his forearm. Other detectorists, such as the finder of the royal Emmerlev ring, hire metalsmiths and jewelers to make re-creations of their discoveries.
The Danefæ program provides a tremendous return on investment from the perspective of the Danish government, Trier says. Private detectorists spend thousands of hours in the fields, and taxpayers pay them only when something extraordinary is uncovered. But simmering frustration with wait times risks upending the program. 'Our system is working really well, but it's only working because the detectorists feel heard—they feel that they are contributing and that we're actually taking them seriously,' Trier says. If processing times get any longer, however, he worries the program will stretch the detectorists' goodwill. 'The trust system only works as long as we archaeologists supply our part of the deal.'
But many detectorists say that even if wait times ballooned, they doubt they'd ever be able to give up their hobby. 'As long as I can walk and dig holes,' Ginnerup says, 'I will continue with my metal detector.'