Found: temple sacred for 3,000 years

The astonishing past: Stone Age site 30 times the size of Stonehenge is discovered as Smith prepares to repatriate bones of Aborigines

Archaeologists have discovered a mysterious 4,700-year-old temple that is the largest Stone Age structure ever found in Western Europe. More than a half a mile across and covering 85 acres, the site in mid-Wales is 30 times the size of Stonehenge.

Archaeologists have discovered a mysterious 4,700-year-old temple that is the largest Stone Age structure ever found in Western Europe. More than a half a mile across and covering 85 acres, the site in mid-Wales is 30 times the size of Stonehenge.

A six-year research programme has revealed that the vast, egg-shaped religious complex consisted of 1,400 obelisks, each towering up to 23ft into the air. Made of oak, they were arranged as an oval with a perimeter of one-and-a-half miles. At its western end, archaeologists have discovered the site of the temple's main entrance - flanked by 6ft diameter timbers that may have stood 30ft tall.

Despite its vast size, the site is baffling archaeologists. They are certain that it had a religious function - but what was being worshipped or venerated remains a mystery.

The focal point appears to have been a natural spring - and possibly some sort of shrine. The complex may have been built on such a grand scale to include a second possible shrine 500 yards north-west of the spring and an area of further ritual activity about 200 yards to the north-east. The main entrance is oriented towards sunset on the summer solstice - the point at which the sun disappears after the longest day of the year.

Detailed examination has revealed that the enclosed area was kept clear for almost 3,000 years. Outside the oval, archaeologists have found a normal level of flint and other prehistoric finds. Inside there have been almost no finds at all.

"They must have kept it extraordinarily clean," said Dr Alex Gibson, an archaeologist who has spent much of the past six years investigating the site for Clwyd-Powys Archaeological Trust. It remained untouched by normal - secular - human activity from its construction in 2700BC, through the late Neolithic and the whole of both the Bronze Age and the Iron Age, which ended after the Roman invasion of AD43.

The absence of debris of human activity from the earlier parts of the Neolithic era suggest the area may have been taboo for even longer - possibly from 4000BC.

After the arrangement of 1,400 oak obelisks was constructed - just before the time that most of Stonehenge was built - it is likely that ordinary people were not just barred from the site, as they probably had been for generations, but were also prevented from seeing inside it. Archaeologists believe planks were used to close the gaps between the obelisks for at least the bottom third of their height.

The temple was almost certainly kept exclusively for the use of the priesthood - probably shamans whose function was to maintain spiritual contact with ancestors and deities.

However, when the Roman invaders arrived, its very sanctity seems to have made it a target. For, in common with many other native British sacred sites - including Stonehenge - the place appears to have been deliberately violated. The Romans seem to have chosen to insult local sensibilities by building first a marching camp on one part of the site and then a permanent fort on another.

The site - at Hindwell, three miles east of New Radnor in Powys - is being seen as one of the most important in Europe. "We were bowled over by the sheer scale of the structure - and the fact that it appears to have remained sacred for thousands of years," Dr Gibson said.