Every year, Israeli high school students and their teachers and advisors descend on patches of ancient land south of Jerusalem. The site of the Third Jewish Revolt, they are there to excavate it, and if they are lucky, to discover something unusual.

And this year, a school official said, something big turned up: a ballista ball, about the size of a very large fist, according to the Jerusalem Post.

The ball, officials think, is a remnant of the war, which is thought to have been fought between 132 and 135 A.D., in which thousands of Jews battled the Romans after years of political and religious persecution. 

The Third Jewish Revolt was the last of several battles fought against the ancient Romans, ending with Roman victory and hundreds of thousands of dead. 

Around 2,000 similar ballista balls have been found on the ancient battleground, the Israeli Antiquities Authority said. The students found the ball in Gush Etzion, a modern group of settlements outside Jerusalem.