|Location Map ( geo)|
|Distance:||4.2 miles (6.8 km)|
|Route outline (key)|
The B4273 is a short B-road in Cwm Clydach in the county of Glamorgan.
The road starts in Ynysybwl at the bridge over Y Ffrwd, with the road in the other direction unclassified. From here it heads southeastward through the village along Clydach Road passing its original 1922 starting point in the village centre.
The B4273 descends the valley to the confluence of Nant Clydach and the River Taff close to Glyncoch. Here there is a sharp bend to the right as the route continues downstream alongside the Taff Vale railway line, which it soon crosses, and the road runs into Pontypridd beside the river. The terminus is at traffic lights on the A4223 just to the west of the bridge that gave the town its name. At one time the road used to continue a little further south along Penuel Lane to end on the A4058.