elizabeth there are records for the burials at talgarth mental hospital, but you must go through the local health authority to prove you are a relative a death certificate of the individual because of the 100 year rule will likely be required also when a patient was admitted to talgarth they had a photo taken at that time , my grandfather john henry avery was admitted in 1922 and i have a picture of him, he died there in 1931 and was buried at the chapel burial ground there is no plot plan so the chance of knowing where on the yard they are is not looking very good. powys archives has that information.