What's longer than a football field and probably older than much of Stonehenge as well as the Egyptian pyramids? According to scientists, an ancient stone monument recently identified in Israel, LiveScience reports. The crescent-shaped structure just a few miles away from the Sea of Galilee is about 492 feet long and 23 feet high and—based on pottery found nearby—was likely built between 3050 BC and 2650 BC. Archaeologists originally thought the monument—known by locals by either its Arabic name or by "Jethro Cairn," after the Druze prophet Jethro, who was Moses' father-in-law, the International Business Times reports—was a city wall, but recent searches around the site have turned up no evidence of an actual city it might have fortified.
The Hebrew University of Jerusalem student who led the excavation surmises that the crescent shape may have been used because the lunar crescent symbolized Sin, a Mesopotamian moon god, and adds that the structure may have served as the border marking for a town located a day's walk away, whose name translates to "house of the moon god." Just as the world has always been fascinated with how the pyramids were built, the Jethro Cairn team set to work trying to figure out the man-hours that went into this project: They believe it took between 35,000 and 50,000 days—an effort scientists estimate would have taken 200 workers at least five months to complete. (A tiny copper awl recently found in a woman's grave in Israel is rewriting history.)