A wine press used 1,400 years ago was recently unearthed by teenagers in the Neve Yaakov neighborhood in Jerusalem.

Local resident Tamar Simon was running with her dog in a nearby wooded area when she noticed the ancient remains. Simon alerted the Israel Antiquities Authority (IAA).

The ancient wine press measures 16.4 feet across, is carved out of a boulder, and has a large square treading floor where grapes were laid down and crushed by barefoot workers. The newly extracted grape juice flowed into a square distributing vat through a conduit also carved into the rock. From there, the juice was moved into a collecting vat.

Amit Re’em, an IAA archaeologist assigned to the Jerusalem District, noted that the wine press had been excavated with care—but that archaeologists hadn’t conducted any dig in that location.

When inspecting the site, the archaeologists spotted a teenager who told them enthusiastically that he and his friends are archaeology buffs and had decided to dig out the wine press together.

“The story touched our hearts and reminded us of our own childhoods,” Re’em said. “However, it’s important to know that a non-methodic excavation results in the loss of valuable archaeological information.”