An army of volunteers is being recruited to help beat erosion which is threatening to destroy historic Barbury Castle.

The 2,600-year-old hillfort, near Wroughton, has suffered damage over the centuries from cattle, sheep, and, in more recent years, human visitors.

It is one of two ancient sites on the Ridgeway which are undergoing repair work.

Liddington Castle is also badly eroded and work there has already started using modern machinery.

But Swindon Borough Council rangers hope people power can be employed to help ensure Barbury Castle will be enjoyed by generations to come.

They are asking volunteers to meet at the far end of the car park at 9.30am on Satur-day.

Work on the hillfort will continue until around 3pm but people can work for as much or as little time as they wish.

All equipment and materials will be supplied, but workers should bring warm weatherproof clothing and a packed lunch.

The procedure involves protecting the original ramparts with a layer of inert polypro-pylene matting, oak boards, small chalk pebbles, and geo-textile netting.

Michael Lilley of Swindon Ranger Service warns that transporting the chalk by wheelbarrow across steep, grassy ramparts to fill in the scars is strenuous work so volunteers will need to be quite fit and in good health.

For health and safety reasons the work day is not suitable for children younger than late teens.

The work is part of the Ridgeway Heritage Project, which is supported by the Heritage Lottery Fund.

It will run from this year to 2005 and has already carried out a full archaeological survey of the Ridgeway National Trail.

Mr Lilley, who is based at Lydiard Park, said: "The Iron Age hillforts of Barbury and Liddington Castles probably date back to around 600BC and may have been used until the Roman conquest of 43AD.

"There would have been timber roundhouses, barns, and granaries inside the ramparts."

Similar repair work was carried out at Barbury Castle between 1978 and 1984, so erosion damage there is less severe than at Liddington. Bar- bury needs about 53 tonnes of chalk infill while Liddington Castle needs 375 tonnes of chalk.