Today only rock-filled postholes remain, surrounded by the enigmatic earthworks of Fort Ancient State Memorial (map). Some are thousands of feet long and all were built by Indians of the pre-agricultural Hopewell culture, the dominant culture in midwestern and eastern North America from about A.D. 1 to 900.
This year archaeologists began using computer models to analyze Moorehead Circle’s layout and found that Ohio’s Woodhenge may have even more in common with the United Kingdom’s Stonehenge than thought—specifically, an apparently intentional astronomical alignment.
The software “allows us to stitch together various kinds of geographical data, including aerial photographs and excavation plans and even digital photographs,” explained excavation leader Robert Riordan, an archaeologist at Wright State University in Dayton, Ohio.
The researchers had known, for example, that an opening in the rings; a nearby, human-made enclosure; stone mounds; and a gateway in a nearby earthen wall are all aligned.
But the model revealed that the alignment is such that, during the Northern Hemisphere’s summer solstice—the longest day of the year—the sun appears to rise in the gateway, as seen from the center of the circle, Riordan said.