"GRAIG is a part of Pontypridd, adjoining on the south side. Norton Bridge, 1 mile east. Trallwin is a part of Pontypridd and adjoins the town on the northeast side." [From Kelly's South Wales Directory 1923 (ArchiveCDBooks) - transcribed by Gareth Hicks]
"Graig is a historic district of the town of Pontypridd, Rhondda Cynon Taf, South Wales, and was historically referred to as 'Rhiw' (hill). The area is closely associated with coal mining and consists largely of terraced housing. Notable collieries within the area include - Gelli-whion (Gelliwion) Colliery, Newbridge Colliery (1844), Pen-y-rhiw (Penrhiw) Colliery (c1870) and Pontypridd Maritime Collieries (1841)..." wikipedia
The church is dedicated to St. John, is in the Benefice of Graig St. John, and the diocese of Llandaff. Details of the present incumbent of this benefice can be found at the Church in Wales website. The church can be located at grid reference ST072896.