Britain's first UNESCO World Heritage Site, Ironbridge in Shropshire, is in danger of falling into the River Severn due to accelerating land slippage in the surrounding gorge.
A new study commissioned by the local council has found that the geological problem - which has been known about for some time - is considerably worse than locals had believed.
Both council officers and UNESCO officials are concerned that as much as 75 per cent of the world's first industrial townscape, which is partially listed, could be under threat from the erosion.
And they have called on the government to provide up to £1.2 million of taxpayers' money to pay for the 'essential repairs' needed to save the buildings.
'The study has revealed that approximately threequarters of the site shows evidence of active or historic instability, ' a report to the local Borough of Telford and Wrekin revealed.
'The potential impact of this is significant, ' it continued.
'Not only are parts of this unique and irreplaceable historic environment directly affected, but also people's homes, businesses and infrastructure.'
But World Heritage Site coordinator Jonathon Lloyd insisted that the site could be saved. 'We simply need the money, ' he told the AJ.
'But in the meantime we are still very much open for business and visitors.'