South Yorkshire's troubled Earth Centre appears to have lost its last chance of a financial lifeline.
School parties were regular visitors to the Earth Centre
The Millennium Commission, which has already pumped £36m into the environmental education centre, has refused further cash help.
The centre at Conisbrough closed its doors in September and plans for it to be taken over by Doncaster Council were abandoned last week.
Centre trustees wanted the money to buy them more time to find other funding.
A Millennium Commission spokeswoman said the Earth Centre's trustees wanted cash to fund an insolvency procedure.
This could have enabled the trustees to continue to look for new backers.
"However the commissioners were not persuaded or convinced that the present efforts to secure new funding were likely to succeed," the spokeswoman said.
"They could not justify spending further public money."
The Millennium Commission spokeswoman said it was now up the Earth Centre's trustees to decide what to do.
The chairman of the trustees, Alan Sheriff, was not available for comment on Friday.
Built on the 400-acre site of a former colliery, the Earth Centre opened in March 1999 and aimed to show people how to live and work in a sustainable environment.
But it consistently failed to reach its expected visitor numbers.
Most of the staff have already been made redundant.