Giant Woodhenge

Magnetic map and excavated post pit

NPS illustration/Bret J. Ruby

National Park Service archeologists recently discovered evidence that a gigantic "woodhenge" once ringed the large circular earthwork at Hopeton. They used a tool called a magnetometer that can "see beneath the soil" and produce a map showing where ancient people disturbed the soil by digging, or where fires for cooking or heating once burned. Near this location, the magnetometer detected a series of disturbances spaced at 20-foot intervals, following the inside edge of the circular earthwork. Archaeologists excavated one of these disturbances and found a large pit where a gigantic timber post once stood, probably two feet in diameter and 20 feet tall. Imagine more than 150 of these spaced out all around the circle! Evidence is mounting that these earthen landscapes were also full of monumental wooden architecture.