Workers Extracting Gravel From the Danube River Dredged Up a 2,200-Year-Old ‘Rusty Treasure’ That Could Have Equipped an Army

Roughly 2,200 years ago, a vessel carrying at least 500 iron bars sank in the Danube River. The treasure remained hidden in the riverbed in what is now Upper Austria for centuries, until a construction crew accidentally unearthed it. Now, archaeologists say the cache represents the largest single discovery of iron bars in Europe.

They describe the “rusty treasure” in a paper published September 21 in the journal Antiquity. The modern saga of the iron bars dates to 2019, when workers extracting gravel near the village of Deinham, on the right bank of the Danube, noticed that their excavator had pulled up several rusted, double-pointed iron objects. They figured the items might be significant, so they alerted Austria’s Federal Monuments Office.

Archaeologists excavating a rock salt mine in Austria recently discovered a well-preserved, 2,000-year-old child’s shoe. After the initial report, archaeologists headed out to Deinham, where they painstakingly searched by hand through the crew’s gravel heaps to try to recover additional iron objects. They ended up with 193 complete iron bars and hundreds of fragments, which together amounted to at least 500 bars.

The bars are shaped “somewhat like a willow leaf,” Gayoung Lee writes for Gizmodo, with one pointed end and one flat. The complete bars are a little less than a foot long, on average, and weigh around 4.5 pounds. The entire cache would have weighed at least 2,200 pounds, the team estimates.

Instead, they believe they were roughly shaped, semi-processed objects that would have eventually been forged into other items. Based on their 2,200-pound calculation, the researchers say the iron would have been enough to make roughly 500 swords or up to 8,000 iron nails. The treasure dates to the third or second century B.C.E., during the late Iron Age, but researchers don’t know much beyond that.

The construction crew’s excavator destroyed the original context of the find, erasing potential clues as to how it ended up in the Danube in the first place. There’s no sign of a boat near where the iron bars were found. However, given the size and location of the cache, the researchers write in the paper that it’s “highly likely” the iron bars were being transported on the river and must have been lost in a shipwreck.