The treasure needed to be secured. So the hoard of 425 gold coins was stowed in a clay jar, its lid secured with a nail, and stashed in the sands of what is now central Israel.

And there it sat, undisturbed, for more than 1,100 years, until mid-August 2020, when two 18-year-olds taking part in an archaeological excavation by a hillside in Yavneh noticed something unusual that turned out to be an ancient treasure.

The teenagers were volunteers in as vast project linked to the construction of a community in Yavneh, south of Tel Aviv. The program offers the promise of connecting young people with history and, while it is meant to be culturally rewarding, it is not often that someone strikes gold — literally.

The coins, which weigh less than two pounds and are made of pure gold, date to the 9th century, when the Abbasid Caliphate ruled a vast empire stretching from Persia in the east to North Africa in the west.

Liat Nadav-Ziv and Elie Haddad, archaeologists at the Israel Antiquities Authority, which is in charge of the sprawling excavation site, said in a statement that the finding “might indicate that international trade took place between the area’s residents and remote areas.” They also said it was clear that the money had been hidden on purpose. We can only guess what prevented the owner from returning to collect this treasure, they said.