Here’s what you’ll learn when you read this story:

• Two metal detectorists located over 3,000 silver coins near Rena, Norway.
• It’s the largest Viking Age coin hoard ever discovered in Norway, and it may continue to grow as the search continues.
• The treasure contains coins from England, Germany, Denmark, and Norway.

A hoard of silver coins left by Vikings in Norway is so massive that even after more than 3,000 coins have been unearthed, the search is still on for more. Initially, a pair of registered metal detectorists uncovered 19 silver coins and called in local officials. By the end of one day of searching, the number of coins recovered had grown to 70. Just a few weeks later, that number passed 3,000, and now the haul is being called the largest Viking Age coin hoard ever located in the history of Norway.

Experts from the University of Oslo’s Museum of Cultural History believe the treasure was deposited near Rena, in what’s now the county of Innlandet, around 1047, shortly after the time when coins started to be minted in the region. The coins found in the hoard come mostly from England and Germany, but a few examples are from those early days of coin-making in Denmark and Norway.

“This is a historic discovery,” Andreas Bjelland Eriksen, minister of climate and environment for the Innlandet County Authority, said in a statement provided by the university. “The fact that it is also from the Viking Age makes it even more spectacular.”

The two metal detectorists were searching in a field near Rena, in a valley called Osterdalen, when their devices went berserk with beeping noises. The pair immediately alerted local authorities, and the find was kept secret to help secure the site. Experts believe the area had never been searched by metal detectorists before. Even now, the location isn’t publicly known and access has been restricted. These precautions make sense given that excavations continue to reveal additional coins that were likely churned up by plowing over the centuries.

“This is completely unprecedented,” said local archaeologist May-Tove Smiseth, according to an article published by Science Norway. “It’s absolutely incredible. I jokingly said it would be nice if we found a few more coins to make the discovery even bigger. But the detectors never stopped beeping.”

Coin experts from the University of Oslo said that the find includes coins minted under Knut the Great, Aethelred II, Otto III, and Harald Hardrada. “The coin hoard includes coins from the 980s to the 1040s,” Svein Gullbekk, Oslo professor, said in a statement. “Foreign coinage dominates the circulation of money in Norway up until Harald Hardrada (1046-1066) established a national coinage.” During Harald’s reign, the king’s own coins started replacing the foreign currencies that were common throughout the Viking Age. Gullbekk said that the newly discovered hoard was stashed at the start of this transition, so it offers a rare insight into the economic connections in Norway during a major political shift.

Museum archaeologist Jostein Bergstol said that the region was known for iron production from the 900s until the late 1200s, with evidence of iron extraction at an industrial scale in the zone around the discovery. Iron ore was extracted from the bogs, and the processed metal was then exported to Europe. Bergstol said that the coin hoard likely represents payments from this type of economic activity, since it wasn’t uncommon for people to store wealth underground, using the soil as a sort of safety-deposit box.

“It has been absolutely unbelievable to stand there and watch these coins be lifted out of the ground,” Smiseth said. “And to see the quality of the coins. They are so beautiful.” She said they look almost newly minted and credits rock-free soil for the preservation.

“We have previously found Viking Age coin hoards containing around 2,000 coins, but never more than 3,000,” Gullbekk told Science Norway. “They have broken a barrier here. This is truly exceptional.”

Work will continue at the site. “This is a truly unique discovery of the kind one might only experience once in an entire career,” Smiseth said. “To be present when something like this comes to light is simply a great experience, both professionally and personally.”