ENGLISH Heritage is to object to putting Silbury Hill on a map showing places where ramblers can walk when the Country-side and Rights of Way Act become law in 2005.

Visitors to the Country-side Agency's roadshow at Marlborough Leisure Centre were surprised to see the ancient monument, the largest Neolithic structure of its type in Europe, highlighted in yellow on display maps indicating it was open country.

Open country is defined under legislation that became law in 2000 as land, other than registered common land, which appears to the Countryside Agency "to consist wholly or predominantly of mountain, moor, heath or down" and is open to ramblers unless otherwise exempted.

But English Heritage has fought for years to prevent visitors climbing Silbury Hill, which has suffered from erosion and the collapse of internal excavations in recent years.

A spokesman said that they had worked closely with Kennet District Council and Wiltshire County Council to create a viewing point close to the 5,000-year-old monument but there was no access to the hill itself.

She added that English Heritage has objected to the inclusion of the monument as being open country in the definition of the Act, and they hoped the Countryside Agency would make the required amendment.

Not only was Silbury Hill coloured yellow on the maps so was virtually the whole of Salisbury Plain including the Larkhill artillery range.

The agency's senior countryside officer Andy Wistow said: "It was the job of the Countryside Agency to identify areas of mountain, moor, heath and down and identify them on the map. But inclusion of these areas does not override existing restrictions like military by-laws and local authority regulations.

"The main purpose of this consultation process is to highlight areas of difficulty and bring them to our attention."

Visitors to the exhibition and presentation at the leisure centre were told they had until midnight on December 3 to register their objections, with relevant evidence.

Using the feedback from the consultation process, provisional maps will be prepared and appeals against them will then be heard before conclusive maps are published.

n Other roadshows will take place at St Margaret's Hall, Bradford on Avon today, from 12.30pm to 7.30pm and at Salisbury Arts Centre on Saturday from 10am to 4pm.