Holy Trinity church was located on the southern edge of Brynmawr, at the limits of contemporary settlement (in 1880) both here and at Nantyglo to the south. Early photographs and maps show that the church, built of dark stone with paler dressings under slate roofs, consisted of nave with short, narrower chancel, small west gable porch and west bellcote, and was lit through lancet windows.
The church was demolished in the mid-1960s to make way for expansion of the nearby Semtex factory (NPRN 41229).
Sources:
Ordnance Survey County Series 25-inch map: sheet Monmouthshire XI.7, edition of 1880.
http://brynmawr.gwentheritage.org.uk/content/catalogue_item/nantyglo-church
http://brynmawr.gwentheritage.org.uk/content/catalogue_item/holy-trinity-church

David Leighton, RCAHMW, 17 November 2015