Prince Charles has backed the campaign to save the building which was Wales' contender in the BBC's Restoration series two years ago.
He made a special request to visit Newbridge Institute and Memorial Hall during a one-day tour of south Wales.
The Grade II Listed building, which came second in the programme's national final, will cost £4.5m to restore.
The prince began his Welsh tour with a trip to the Engine House Community Project in Dowlais, Merthyr Tydfil.
He then moved on to the Newbridge Institute and Memorial Hall, which was opened in 1908 to serve the area's mining community.
It is used for local events and there is an old cinema upstairs, which dates from 1924 and closed in the 1960s.
Sybil Griffiths has been connected with the hall since 1942
There are hopes to reopen it with seats for 400 people.
During his visit, Prince Charles told BBC Wales: "We owe it to those who built [it], I think, and also to the meaning behind it, telling the stories.
"I think they have done a huge amount of work in showing it could be viable with all these uses and wonderful community activities.
"It would be so wonderful to have it all here."
The prince promised to come back when the £4.5m worth of work which needs doing is complete, which campaigners hope will be in about five years' time.
The prince spoke to volunteers and staff, including cleaners Anne White, Sheila Hopkins and Shirley Bourne.
Mrs Bourne said: "He was asking us about the village, what facilities we had and I stressed that we need this place to survive. He said, 'I know, that's why I'm here'.
"I'm very glad that he's taken such an interest in this wonderful building. He even joked with us that he hoped that he wasn't going to create any extra cleaning for us!"
The prince also met Sybil Griffiths, whose connections with the hall go back nearly 65 years.
The prince finished his visit in Newport
She said: "I've been involved with the Memo since 1942, when I worked with the South Wales Miners' Federation. He was asking all about the cinema and what I could remember.
"He was very interested in what it was like years ago."
The prince looked at cinema memorabilia and old record books before completing his trip with a visit to the Taste of Enterprise Centre at the Victorian indoor market in Newport.
Around 50 people greeted him as he arrived at the building and went up to its second floor and visited stalls established with the help of Prime Cymru, one of the prince's charities, aimed at promoting self-employment and enterprise for people over 50.
One of the businesses was Knitwitches Yarn, run by Eirwen Godfrey and Jane King.
They presented Prince Charles with a knitted birthday cushion, it was his birthday yesterday, and with a 100% pure silk scarf for the Duchess of Cornwall.
Ms Godfrey said: "I designed the scarf myself and it would be rather wonderful if I saw her wearing it.
"He asked me if I could knit scarves while I was watching the television and I said "I can but not this one, I couldn't even listen to the radio."
The prince's last trip to Wales was in July, when he finished his traditional summer tour of the country with a surprise visit to the International Eisteddfod in Llangollen.