Sprawling rectangular structures scattered across northwest Arabia and dating back more than 7,000 years may have been part of a prehistoric cattle cult, researchers have found.

More than 1,000 of the mysterious structures, referred to as mustatils (an Arabic word meaning “rectangle”), have been documented in Saudi Arabia. While their appearance varies, they are usually rectangular in shape and often consisting of two platforms connected by two walls. Archaeological work indicates that some of the mustatils had a chamber in the center made of stone walls surrounding an open area with a standing stone in the center.