On May 25, 2023, a diver off Sardinia noticed something metallic in the seagrass near Arzachena. The first object led investigators to a much larger cache: tens of thousands of late Roman bronze folles, with Italy’s culture ministry estimating the total at more than 30,000 coins and possibly as many as 50,000.

“The treasure found in the waters of Arzachena represents one of the most important discoveries of numismatic finds in recent years,” Luigi La Rocca, director general of archaeology, fine arts, and landscape for the region, says in a translated statement from the Italian culture ministry.

The search centered on a sandy clearing near the beach, bordered by seagrass. From there, divers recovered coins in what the ministry described as an “excellent and rare state of preservation.” The original official statement placed the coins between 324 and 340 CE. Later reporting from a December 2023 presentation in Sassari said a studied sample dated the coins from 324 to no later than 345 CE, with roughly 40,000 folles as a working figure. The safest number is still a range: at least 30,000 coins, and possibly up to 50,000.

And, if we’re lucky, it may even point to a completely undiscovered hidden shipwreck.

The ministry’s original statement treated a wreck as a possibility. The coins were found across two large areas of dispersion between the beach and posidonia seagrass, and divers also documented fragments of narrow-necked amphorae. That pattern could fit a wreck scenario. It could also remain murkier than that until a final archaeological interpretation is published. Public sources reviewed for this update do not confirm a wreck, a final coin count, or a formal scientific catalog of the hoard.

Right now, we will have to content ourselves with the excitement of the huge bounty of coins discovered littering the seafloor. The follis coins—found in both bronze and copper—were used first by the Romans and then later by the Byzantine Empire.

After the find, the diver contacted authorities, and teams from Italy’s art-protection police, the ministry’s underwater archaeology office, firefighters, and border police joined the recovery work. Alongside the coins, divers found fragments of amphorae—narrow-necked storage vessels with two handles—which helped fuel the shipwreck hypothesis.

The discovery also moved from archaeology into court. In a January 5, 2026 decision, TAR Sardegna rejected the finder’s claim for a statutory reward. According to the ruling, the court did not treat the discovery as fortuitous, citing the use of a metal detector and evidence that the area was already understood as potentially archaeologically significant.

There’s one more practical question: where will the hoard end up? Reporting from a December 2023 public presentation said part of the cleaned and cataloged material was expected to be assigned to Arzachena’s civic museum, though as of May 2026, the hoard isn’t yet on display. So while the coins may eventually help tell Arzachena’s own story, there’s no public confirmation that the transfer or display has already happened.

“(The finding) highlights the richness and importance of the archaeological heritage that our seabed, traversed by men and goods since the earliest times, still guards and preserves,” La Rocca said.