|Length:||3 miles (4.8 km)|
|Route outline (key)|
The B4256 is another of the B-roads going across the moors from one Welsh valley to the next.
It starts on the A4048 on the edge of Tredegar. It heads northwest along the pre-bypass A4048 into Tredegar itself before turning sharply left by Castle Street Church onto Queen Victoria Street. It heads more-or-less southerly out of town, climbing as it does so, before a bend to the right leads through the cemetery into open country.
After a mile or so of moorland the road descends again into the next valley and the next town, Rhymney. The mainline of the road continues along Hill Street to end on the B4257 (former A469) to the south of the town centre. The angle of this junction is only really suitable to allow traffic to turn right, so there is also a spur of the B4256 slightly further south along Moriah Street which also leads to the B4257.