The Parthenon once housed a massive statue of Athena made of ivory and gold; researchers now say it was far from the only thing of value kept in the ancient temple. Though the attic of the Parthenon has long been destroyed, researchers believe it once held millions of silver coins that have long since been spent, LiveScience reports. Ancient writers gave only the vaguest of clues about where Athens stored its coins—in 433BC it was written that "3,000 talents" had been moved to the Acropolis, and that the city's reserves could get as high as 10,000 talents. One talent is equal to 1,500 silver tetradrachms—then the highest-denomination coin made in Athens—meaning up to 15 million tetradrachms. So what led researchers to believe all those coins were kept in the attic?
The remains of a non-ceremonial staircase leading to the attic, for one. Further, "the attic of the Parthenon is the only suitable space large enough to hold all of the coins in the Treasury," researcher Spencer Pope tells LiveScience in an email: He estimates it was a roughly 10,168-square-foot space, meaning it had enough space to properly distribute the coins' weight: 15 million tetradrachms could have weighed as much as 287 tons. Plus, "while we cannot rule out the possibility that coins were distributed across numerous buildings, we should recall that the attic is the most secure space," says Pope. That statue of Athena may have helped: Ancient Origins runs down a list of the woes Athena could inflict upon those who crossed her; fears of being turned blind or mad by the goddess may have kept thieves at bay. (The Acropolis isn't doing so well.)