Talgarth was initially to serve Breckonshire and Radnorshire, however after WWI patients were also admitted from Montgomeryshire.
During the Second World War Cardiff Mental Hospital was used predominantly for military casualties and as such patients were transferred to Talgarth. In 1940 Talgarth was itself seconded to military use and its “residents” were transferred to other mental hospitals in Wales. This remained the case until 1947.
The hospital eventually closed its doors in 1999 and the site, in my view rather controversially was sold to the former chief medical officer for a mere £227,000.
A business venture to turn the site into a business park hit the skids in 2009 due to a downturn in the Global Economy and the site was offered up for sale again. Sadly by this time most of the slates from the buildings roofs had been stripped and most likely sold for profit.