The Brunel-built railway viaduct in Chippenham is among a host of North Wiltshire landmarks identified as being at risk by history watchdog, English Heritage.

The organisation's annual Buildings At Risk register, published last week, finds many buildings and monuments are in danger of falling into disrepair, or even being lost forever, unless more money is spent on their protection.

The nine archways of Chippenham's railway viaduct have stood in the town since 1841, but the report shows it is in urgent need of renovation work.

The viaduct still plays an important part in the area's railway network, but water and salt damage is causing parts of the construction to crumble.

Last year, New Road was closed by police after apiece of masonry fell from the bridge on to the road below

Nicola Sterry, the historical buildings inspector for English Heritage, has visited the viaduct with representatives of North Wiltshire District Council and Railtrack.

"This is a very important monument and we have been liaising closely with North Wiltshire District Council and Railtrack to identify and resolve the problems," said Ms Sterry.

"Unfortunately, water seepage is wreaking havoc on some parts of the brickwork, while salts contained in the water have got into the stone work and expanded, causing some of the stone to fall away.

"We have advised North Wiltshire District Council and Railtrack that urgent work needs to be undertaken to protect the building.

"But, while it is important this is done to protect the viaduct, Railtrack obviously faces the issue of closing this busy rail route so the work can be carried out."

North Wiltshire District Council spokesman Paul Langcaster said: "We have met with Railtrack and English Heritage to discuss the future of the structure and some repairs have been carried out, but there still appears to be work needing to be done. We have been told the work has been budgeted for 2004-2005."

In Calne, the faade of the Lansdowne Hotel in The Strand, hides a dilapidated former coach house, stable and brewhouse, which have been standing there since the 17th century.

Highlighted as in poor condition by English Heritage, the buildings, which range from the mid 17th century to the mid 19th century, are at risk because of the condition of their roof structures and coverings, which are continuing to degenerate, leading to internal decay.

Mr Langcaster said: "We have been trying to persuade the owners to take action. However work has not been carried out and there is little we are able do apart from issuing a urgent works or urgent repairs notice."