The remains of a major new prehistoric stone monument have been discovered less than 3 kilometres from Stonehenge. Using cutting edge, multi-sensor technologies the Stonehenge Hidden Landscapes Project has revealed evidence for a large stone monument hidden beneath the bank of the later Durrington Walls ‘super-henge’.

The findings were announced on the first day of the British Science Festival, Monday 7 September, hosted this year at the University of Bradford.

Durrington Walls is one of the largest known henge monuments measuring 500m in diameter and thought to have been built around 4,500 years ago. Measuring more than 1.5 kilometres in circumference, it is surrounded by a ditch up to 17.6m wide and an outer bank 40m wide and with a height of 1 metre.

The monument was on "an extraordinary scale" and unique, researchers said.

The Stonehenge Hidden Landscapes team has been creating an underground map of the area in a five-year project.

The monument is just under two miles (3km) from Stonehenge, Wiltshire, and is thought to have been a ritual site.

The stones are believed to have been deliberately toppled over the south-eastern edge of the bank of the circular enclosure before being incorporated into it.

Lead researcher Vince Gaffney, of the University of Bradford, said: "We don't think there's anything quite like this anywhere else in the world.

"This is completely new and the scale is extraordinary."

Archaeologist Nick Snashall said: "The presence of what appear to be stones, surrounding the site of one of the largest neolithic settlements in Europe adds a whole new chapter to the Stonehenge story."