Grwyne-fawr, Breconshire Genealogy
The Grwyne Fawr is a river in the Brecon Beacons National Park in south Wales. A section of it forms the administrative border between Powys and Monmouthshire and also of the historic counties of Brecon and Monmouth. (Wikipedia)
Census records from 1841 to 1911 are available online. For access, see England Census Records and Indexes Online. Census records from 1841 to 1891 are also available on film through a Family History Center or at the Family History Library.