DEBTS of £300,000 have cast doubt on the future of the Welsh International Climbing Centre in the Taff Bargoed Valley.
The attraction draws 70,000 visitors a year and employs 40 staff.
Its fate depends on an emergency meeting.
Coun Leighton Smart said the closure could also stall any further regeneration projects in Trelewis.
He said the centre had "old debts" and, although it was making a profit, was unable to "service those debts".
The centre opened 10 years ago on a former pit site and cost more than £1m to build with cash backing from the Welsh Office, the Millennium Commission, the Groundwork Trust and Europe.
It has since become one of the biggest indoor climbing centres in Europe with visitors from across the UK practising climbing, caving and kayaking skills.
The centre is owned by the Taff Bargoed Development Trust but is run by Business Enterprise Support.
Business manager Denziel Davies was unwilling to comment on the centre's financial situation.
Mr Davies also made it clear that no one from the centre or trust was willing to speak about the matter.
Coun Smart said: "A tremendous amount of public money has been on the centre - and to create work for local people - after the closure of three pits, with the loss of 1,200 jobs and £6m from the local economy.
"It's owned by the people of Bedlinog, Trelewis and Treharris.
"We can't let it go, something has to be done. If we can't save it then we can kiss goodbye to continuing regeneration of any of our communities here."
There was a hint of problems 18 months ago with the closure of the centre's caf and the loss of five staff.
Coun Smart said the centre had not received the promotional support of the Wales Tourist Board because of lack of regeneration or visual improvement in the surrounding area.
"We now have consultants putting together a long-term regeneration strategy," he said.
Groundwork Trust spokesman Andy Carter said: "The funding we have raised to invest in regeneration is protected by deed of dedication.
"It means assets like the climbing centre are protected from business difficulties."
Assembly Member for Merthyr and Rhymney, Huw Lewis, is understood to have been working with the management of the centre and other Government agencies.