Archaeologists are slowly uncovering evidence of a 2,000-year-old ceremonial site that resembles a wooden 'Stonehenge' near Cincinnati, Ohio.
Laid out in a peculiar pattern of concentric, but incomplete, rings, the site is about 200 feet (57 meters) wide.
The site, formally called Moorehead Circle but nicknamed 'Woodhenge', now contains only rock-filled postholes remain, surrounded by the enigmatic earthworks of Fort Ancient State Memorial.
Some are thousands of feet long and all were built by Indians of the pre-agricultural Hopewell culture.
A software "allows us to stitch together various kinds of geographical data, including aerial photographs and excavation plans and even digital photographs," National Geographic News quoted excavation leader Robert Riordan, an archaeologist at Wright State University in Dayton, Ohio, as saying.
The alignment of the site revealed 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 centre of the circle - much like Stonehenge.
It must have been a mammoth task to build the site, said Riordan.
"They would have had to dig these holes, go get the trees, cut them, strip them, and carry them in," he said.
Not even digging the postholes would have been easy. Lacking shovels or picks, the Hopewell people dug with bones and sharpened pieces of wood.
"This was an elaborate construction," he added.
"All the effort that went into constructing it suggests it was the ceremonial focus of Fort Ancient for a time." (ANI)