LLANGWM UCHAF and LLANGWM ISA, or Upper and Lower Llangwm, are jointly one parish, near the road from Usk to Chepstow and about 2 miles south of the road from Usk to Monmouth, 4 miles east from Usk station on the Coleford, Monmouth, Usk and Pontypool section of the Great Western Railway, 9 north-west from Chepstow and 15 north-east from Newport, in the Southern division of the county, hundred and petty sessional division of Usk, Chepstow union, Usk county court district, rural deanery of Usk, archdeaconry of Monmouth and diocese of Llandaff.
Source: Kelly's Directory of Monmouthshire,1901