In Denmark, archaeologists have found a series of ancient fences arranged in concentric rings, closing off a huge area about the size of two large sports fields, the New Historian reports.
The fences were found this past September and enclose an area of more than 21,500 square yards. There are five rows of fences, one inside the other, which date back to the Neolithic period, which ended around 2,000 B.C. The rings were made from poles about six and a half feet in length.
Most mysterious, though, is the way in which they were arranged. The openings in each ring of fence were offset from each other—from the outside, you wouldn’t have been able to see the interior of the fenced in area, or walk straight through. The openings were big enough, though, that the archaeologists who found the fence don’t think the fences were necessarily meant as a defensive measure. Rather, they’re more like a maze.
Nothing has yet been found in the interior area, though, that suggests what the purpose of the space was. It may have been used for a ritual purposes, but “to put it simply, we just don’t know,” archaeologist Pernille Rohde Sloth said.