Stonehenge comes within virtual touching range

This summer, for the first time, it will be possible to get your head round Stonehenge. Visitors who want to ponder the message of the ancient stones will be able to scrutinise them as closely as they like, using a virtual-reality headset which generates a three-dimensional image.

English Heritage, which administers the ancient monument in Wiltshire, will next month demonstrate in Salisbury a computerised version of the 5,000-year-old site. Using virtual reality, the user will be able to "roam" anywhere inside an exact simulacrum of the concentric circles of ancient stones.

The images have been recreated from geological, photographic and laser imaging data, so users can view details and contours ranging over an area of more than a square mile around Stonehenge itself.

At the moment it is impossible to get near to the actual central circle of towering stones, which has been cordoned off by a low fence since 1978. This keeps people up to 40 feet away to prevent damage to the stones and their surroundings, and give everybody an equal view of the site.

Visitors pay pounds 3 for access, but Stonehenge's popularity remains undiminished: on a busy day there are up to 6,000 visitors and last year a total of 708,000 people passed through the official Visitor Centre, an increase of 18 per cent on 1994.

The virtual-reality alternative would allow a visit without the bother of crowds, doubtful weather or access restrictions. "Rather than having to go to the stones in real life, you will have the real thing there on the computer that you can effectively walk around," according to Andrew Dennison, a virtual-reality application developer at VR Solutions of Salford, which is recreating the site in software. Early uses are likely to be in the Visitor Centre at Stonehenge itself, and for examining the potential effects of any changes - such as road layout - on the site's appearance.

In future, CD-ROM and Internet versions of the virtual- reality site may also be put on sale so that children and adults around the world could experience the site's layout without needing to go there.

The building of Stonehenge is thought to have begun around 3,000BC, in the late Stone or early Bronze Age. A number of elements were added in the succeeding centuries, including stones brought from the Welsh mountains and Pembrokeshire. The purpose of the site, ruined during the Roman occupation, is unclear. However, the orientation of a number of the important stones suggests that it had a religious significance which was also connected to the seasons' solstices.

Brian Hath, English Heritage's head of design and interpretation, said that the computer model will "make Stonehenge accessible to many more people without impacting on the stones, landscape and nearby archaeological remains".

Another version of the model, being prepared by the British company Superscape, will allow computer users to "visit" the site as it might have looked at any date past or future and see how at the solstices, sunrise and sunset highlight particular stones.