A charitable trust that managed Cornwall's industrial heritage sites has ceased operating.
The Trust was set up to look after historical sites
The Trevithick Trust was set up 14 years ago by local authorities to run museums and historical sites in west Cornwall for their owners.
But concerns were raised about the way it operated and it lost control of some of the sites.
Kerrier and Cornwall County Council has now withdrawn funding, forcing its closure with the loss of four jobs.
It leaves the future of the ruin of the Old St Day Church uncertain, although the King Edward Mine will now be managed by a limited company.
Peter Jennings, the Trust's acting general manager, said: "The decision to close the Trust is a sad day for the future of Cornwall's industrial past.
"The decision makes no economic sense as the Trust has had a genuine impact on interpreting the history of Cornwall's industrial heritage and saved many sites."
Kerrier councillor John Woodward said he was extremely disappointed that the high aspirations for the Trust were never delivered.