London, England (CNN) -- Archaeologists studying the iconic Stonehenge monument in southern England have uncovered a second prehistoric henge-like circle only 900 meters away, which they hope will shed more light on the mysterious stone landmark.
The remains, comprising a circular ditch surrounding a ring of 24 internal pits up to one meter in diameter and designed to allow posts to support a free-standing, timber structure up to three meters high -- are thought to date from the late Neolithic period, some 4,500 years ago.
"Although it would have been made out of timber rather than stone, it's comparable in scale to the existing Stonehenge monument," said Henry Chapman of the University of Birmingham in central England.
Chapman was one of the British-led team involved in a multi-million dollar project to "map" the World Heritage site, using state-of-the-art imaging technology to recreate "virtually" the iconic monument and its surroundings.
The images, which resemble a lunar landscape, provide an outline of the circle buried under the surface with its opposing north-east and south-west entrances, together with what archaeologists believe to be a burial mound in the center.
CNN
