|Distance:||12.9 miles (20.8 km)|
|Meets:||A659, A59, B6165|
|Route outline (key)|
The B6451 is a cross-country road in central Yorkshire. It was originally unclassified but had gained its number by 1932.
The road starts at a signalised staggered crossroads on the A659 in the centre of Otley and heads north along Kirkgate before zigzagging right then left onto Bridge Street. The bridge (over the River Wharfe) is soon crossed, after which there's a badly signed TOTSO right. We continue through the suburb of Newall and climb into open country. At Thornberry Hill, TOTSO left, (the C238 goes straight ahead to the narrow bridge over the River Washburn, joining the B6161 just south of Leathley village).
By the gates of Farnley Hall there's a TOTSO left and we zigzag northwards through Farnley itself before descending into the valley of the River Washburn. Lindley Wood Reservoir can be seen to the right and we cross its upper reaches before climbing steeply out of the valley. After a brief wooded section we come out of Sandwith Moor and continue on, with a view of more reservoirs in the Washburn valley to the left. We cross a couple of tributaries as we continue north.
Presently, after a dead-straight section we reach the ominously named Dangerous Corner, where we cross the A59. The name of the junction may have something to do with the fact that both roads crossing here are dead-straight for some distance yet visibility isn't that good. We continue past RAF Menwith Hill, a huge electronic monitoring station. "Golf balls" or radio receivers can occasionally be seen behind the vegetation on the right. There's a turn to the station at the next crossroads, after which the road starts to descend steeply.
After passing the western edge of Darley we cross the Darley Beck then climb to run through the village of Dacre. There's another descent on the far side as the road goes through Dacre Banks then winds to pass between a timber yard and a bowling green and cross the River Nidd. Now in Summerbridge the road climbs and ends shortly afterwards at a T-junction on the B6165.