Is it or isn't it? Even the experts seem to be divided. It seems fairly clear that there was a Roman road across the Pennines linking Manchester (Mamucium) with what is now Ilkley in West Yorkshire and the old road over Blackstone Edge Moor is certainly old. However the stone surface which can still be clearly seen is relatively recent and so are the carvings on the Aggin Stone. The route was well-used by packhorse trains and other travellers in medieval times and only faded into relative obscurity with the advent of canals, turnpike roads and railways.

Old trading route

The best guess of the age of the existing masonry is probably less than 200 years. This may seem a let-down if you're sold on the Roman connection and want to add another nought, but on reflection it's still quite impressive. And those old stones are highly evocative, whether you choose to imagine Roman legionaries tramping up the steep incline, or 15th-century merchants and their trains of horses laden with bales of wool or barrels of salt. Romans or merchants alike would surely have regarded these high, exposed moors as an awkward obstacle to be surmounted, not as an attraction to be sought out.

The Pennine Way was the first long distance path to be proposed in the UK and the first to be opened, being officially inaugurated in 1965. It stretches from the Peak District to the Scottish Borders with a pub conveniently marking each end: the Old Nags Head in Edale and the Border Inn at Kirk Yetholm. In between lie 268 miles (431km) of walking of which the stretch over Blackstone Edge is a fair sample.

The huge popularity of the walk has created problems with erosion in a number of places. In fact stories about erosion may have contributed to a decrease in the numbers now tackling it, though the main factor is the great expansion of a network of other long distance paths, from the South West Coast Path to the West Highland Way. These days far greater concerns about erosion result from inappropriate and illegal use of motorbikes and four-wheel drive vehicles.

The rocks of Blackstone Edge stretch for about 0.5 miles (800m) and have some appeal for rock climbers. The main climbing area is north of the trig point where there are about two dozen routes. Of course this walk is not solely about the ridge. It starts and finishes in softer country dotted with old farms and weavers' cottages. At Syke Farm, near the end, there's another ancient lane. And the hill just above is called Benny Hill, which will amuse some people hugely and others not at all.

Follow the drive beyond the visitor centre through a gate. As it later swings right, take the path ahead past a picnic area, crossing a brook shortly afterwards to emerge on a track by Lane Foot. Go left 200yds (183m) and then leave sharp right through a waymarked gate. Over a rise, drop to a footbridge and follow the ongoing path, which climbs along the flank of a wooded valley above Shore Lane Brook.

At the top, cross a slab bridge and bear right through more trees to emerge onto a golf course. Watching for golfers, cross the fairway and continue along a broad path. Later, join a track from Owlet Hall and carry on, eventually passing Shore Lane Farm to meet a lane. Go left to Lydgate.

As you approach a road junction, turn right on a track past terraced cottages. Go through a gate at the end and follow a clear path rising beside a wall onto the moor, in time meeting a farm track by the A58. Go right but then bear off left before a gateway to follow the 'Roman Road' up the hillside. Keep going beyond the cut of Broad Head Drain to reach the Aggin Stone.

Turn right through a kissing gate and follow a rough path across the rock-strewn moor, passing the trig point to reach a wall shelter, some 400yds (363m) further on.

Turn off half right, heading southwest to descend through a gap between the rocks of the edge. Continue down across the hillside, soon picking up a cairned trod that leads down to Broad Head Drain. (Aim for the base of a clear path onto Hoar Edge opposite, but in mist, take a more westerly heading, dropping to the drain and following it left.) Take the rising path onto Hoar Edge, climbing to a cairn on the crest. Beyond, the path gently falls, later passing above a dark pool at the base of a deep hollow, Dry Mere.

Just beyond the tarn, the path fragments; keep ahead towards a pylon. As the path winds below it, cross a broad track and carry on down to a second track. Go left, dipping to ford a stream and continuing down to a gravel track. To the right, it descends below the wooded flank of Benny Hill to cottages at Syke Farm.

Joining a lane from the right, follow it downhill past Hollingworth Fold. At the bottom, turn right above the lake and walk back to the car park.