|From:||Llanvihangel Crucorney (SO325207)|
|Distance:||6.1 miles (9.8 km)|
|Route outline (key)|
The second incarnation of the B4423 ran in northern Monmouthshire. The road, originally unclassified, gained its number in 1935. However, it was declassified again in the late 1970s and remains so.
The road started on the now-bypassed original route of the A465 in the centre of Llanvihangel Crucorney. It descended steeply into the valley of the River Honddu but bore left before crossing the river to follow the valley upstream. It soon went under the railway line from Hereford to Newport.
The B4423 remained as a narrow road along the bottom of the valley. It passed through small, scattered settlements such as Stanton and Henllan but no places of any size. Nor were there many side roads, perhaps owing to the steepness of the valley sides. After a number of bends and a crossing of the River Honddu the road reached Llanthony. It ended at a road junction that even today is easy to miss, with the other roads unclassified. The road to the right reached the priory ruins whilst the road ahead continued over the hills via Capel-y-ffin, ending in Hay-on-Wye.