Stonehenge's newfound sister henge—marked as the "New Henge" in the map above—may add to the slowly emerging picture of the region's prehistoric spiritual landscape.
Stonehenge itself is linked to a timber circle called Woodhenge via the River Avon and an ancient road called the Avenue. Though close to Stonehenge, the newfound site is even closer to the Cursus, a huge, stretching earthwork dated to around 3,500 B.C.
"Before Stonehenge was constructed, [the Cursus] was the principal monument in that landscape," said Joshua Pollard, an archaeologist at the University of Bristol who isn't involved in the new survey.
It's possible that the Stonehenge complex started off "with a series of small stone circles which are actually focused on the Cursus itself," Pollard said.
(Related: "Stonehenge Was Cemetery First and Foremost, Study Says.")