LONDON - Archaeologist say they have discovered a major prehistoric monument beneath the Earth near Stonehenge that could help led to the origins of the mystical stone circle in England.

Experts from British universities led by University of Bradford says at least 20 huge shafts, forming a circle more than a mile in diameter located about 1.2 miles from Stonehenge, was found.

According to ABC News, researchers say the shafts appear to have been dug around 4500 years ago and could set the boundary of a sacred area or precinct around a circular monument known as the Durrington Walls henge. 

University of Bradford archaeologist, Vince Gaffney, says its "remarkable" that a place like Stonehenge could yield such a new discovery. 

“When these pits were first noted it was thought they might be natural features — solution hollows in the chalk,” he said. But geophysical surveys allowed scientists to “join the dots and see there was a pattern on a massive scale.”

Mysterious stone circles built thousands of years ago are scattered all over Britain.

The most famous is Stonehenge, a huge monument built between 3000 B.C. and 1600 B.C. that is one of Britain’s most popular tourist attractions.