A4125 (Little Mill - Abergavenny)

This article is about the original A4125, now part of the A4042.
For the current A4125 near Watford, see A4125.

The A4042 (former A4125) in Llanover

The A4125 was a short-lived A-road in east Monmouthshire.

The road started at Little Mill, to the east of Pontypool on the A472. It then headed north, shadowing the railway line for its entire distance. Road and railway line ran close as far as Penperlleni but then diverged, with the A4125 following a hillier route to the west. Presently the road crossed the River Usk to return to the railway line and end on the A471 (now B4598) to the south of Abergavenny.

The route was originally numbered B4245 and became the A4125 in the late 1920s. In 1935 it was renumbered as a northern extension of the A4042. It remains this number, although the junctions at both ends have been rebuilt, that at the northern end considerably so.