A 13-year-old schoolboy discovered a rusty coin in a field on the outskirts of Berlin that researchers identified as a rare artifact from ancient Greece — but no one knows how it got there.

The abandoned relic was found in a field that was a popular archaeological site between the 1950s and 1970s, according to the Smithsonian Magazine.

The boy wound up becoming the first to ever find a Greek artifact in the German capital, the outlet reported.

Most goods previously excavated from the field were linked to the Iron Age, which spanned from 800 to 450 BCE.

The burgeoning antiquarian pocketed the coin and, in November 2025, innocently showed it off to researchers at a local archaeology lab.

Even the experts struggled to identify the coin.

“Nobody knew exactly what it was because it was so small. That it was something old was clear,” Jens Henker, an archaeologist with the Berlin Heritage Authority, told the magazine.

A numismatist, or a professional coin enthusiast, from the lab later identified it as a Trojan coin minted between 281 and 261 BCE, according to a news release.

The faded bust stamped on it depicts Athena, the Greek goddess of war and wisdom, wearing a Corinthian helmet. The tail features the same deity in a kalathos headdress, armed with a spear in one hand and a spindle in the other, the release said.

Experts originally suspected a well-known collector in Berlin might have misplaced the coin before they learned about the field where the boy found it.

Henker surmised that Germanic-speaking nomads who used to live in what is now Berlin likely used the precious metal in the 12-millimeter coin to make supplies.

Coins that weren’t melted down were commonly left in burial grounds “as a kind of grave gift,” Henker told German outlet Deutsche Welle.

“This appears to be like a souvenir used to remember something—perhaps even an experience in one’s life,” he said.

No one, though, could determine how the coin traveled from ancient Troy to Berlin.

When ancient Greece was thriving, northern and central Europe were largely unexplored.

Pytheas, the first known Greek person to trek beyond the empire’s “known world,” recorded his discovery of communities in other regions, but was written off because his findings didn’t match the majority’s perception of foreign “barbarians.”

“They said, ‘He’s spinning this. There’s no way that it exists,'” Henker told the outlet.

Henker suggested the coin changed hands through trade or bribes to recruit Germanic-speaking peoples as soldiers, but struggled to find a firm hypothesis.