A pavilion which was temporarily closed last month due to asbestos concerns will be permanently shut.
Denbighshire council said it was with "great regret" it was closing Corwen Pavilion due to the state of the site.
It is a popular venue for concerts and meetings, and hosted the first Urdd youth eisteddfod in the town in 1929.
Council leader Hugh Evans said problems with the building had increased to the point where little could be gained from using "a sticking plaster" approach.
"This really is devastating news, not only for the people of Corwen but for Denbighshire as well," he added.
"Unfortunately we have been left with no option but to take this drastic course of action."
The council said as part of preliminary investigations for a planned minor refurbishment surveyors found "substantial electrical faults" throughout the building which could result "in significant risk to life".
Other surveys carried out by North Wales Fire and Rescue Service found numerous fire safety problems along with limited fire detection and safe evacuation for members of the public.
The council said further potential health risks were found, including the risk of cross-contamination due to a lack of appropriate welfare facilities.
Head of leisure and youth services at the council, Jamie Groves, said: "This is a real setback and is very disappointing news.
"We had raised a substantial amount of funding, which was to be invested in the building, but the results from the investigations mean that the building is not safe and is no longer fit for purpose.
"We aim to help with redirecting existing bookings and we intend to meet with the community as soon as possible to explain the situation.
"We will work with them to provide an alternative facility which is fit for the 21st century."