LONDON: A vast complex of monuments surrounding Britain’s prehistoric Stonehenge site has been revealed using hi-tech underground scanning, archaeologists said on Wednesday.

The mysterious circle of standing stones, on Salisbury Plain in southwest England, is one of the most iconic ancient sites in Europe and was long thought to stand alone.

But high-resolution scanning of the 12 square kilometres around it, penetrating three metres below the ground, has found it was surrounded by 17 neighbouring shrines.

“Stonehenge is the most iconic archaeological monument, possibly along with the pyramids, on the planet,” project leader Professor Vincent Gaffney told the British Science Festival in Birmingham, central England.

“Most of the area around Stonehenge is terra incognita. It has never been explored and everything we think about Stonehenge is on the basis of what we don’t know about it.

“This is going to change how we view Stonehenge. It is not yet another find from Stonehenge, it’s a fundamental step forward in the way we understand it.”

The four-year study used magnetometers — advanced metal detectors — ground-penetrating radar, electromagnetic sensors and three-dimensional laser scanners.

It uncovered finds dating back 6,000 years, including evidence of 17 previously unknown wooden or stone structures as well as dozens of burial mounds.

They include giant pits, some of which appear to form astronomical alignments.

The nearby Durrington Walls “super-henge”, which has a circumference of nearly 1.5 kilometres, was once flanked by up to 60 posts or stones up to three metres high, the scans showed.

Many burial mounds were found, including one barrow 33 metres long, within which signs of a giant timber building were found.

Published in Dawn, September 11th, 2014