Walk 20 Llewellyn’s Cave and Aberedw Rocks
Walk 21 Llandeilo Hill and Twm Tobacco’s Grave
Walk 22 Builth and Banc-y-Celyn
The Upper Wye: Newbridge-on-Wye to Plynlimon
Walk 25 Above the Elan Valley reservoirs
Walk 29 Llangurig to Llanidloes
Walk 30 Plynlimon and the source of the Wye
Appendix A Route summary table
The Wye as an upland river at Pont Marteg (Walk 28)
INTRODUCTION
Looking back to Weobley from Garnstone Park (Walk 14)
The Wye may be only the fourth longest river in England and Wales, but it is almost certainly the most scenic. The author George Borrow went further, describing it as ‘the most lovely river, probably, the world can boast of’. The Wye concocts a magical blend of the best of British landscapes, from open moorland in the upper reaches through pastoral tranquillity in the lowlands of Herefordshire to the final miles of its journey through a densely wooded limestone gorge to the Severn Estuary. This diversity of landscape supports a richly varied ecology, with the whole of the lower and middle Wye designated for their nature conservation importance.
It is not just the natural history of the river that is so compelling. For centuries the Wye has been a border river: in Iron Age times hillforts defended key locations on either side of the river, while Offa’s Dyke was thrown up in the eighth century to keep the Welsh at bay and a string of castles sought to underpin Norman control of the troublesome Welsh Marches. Trouble flared again in the Civil Wars, when the territory – and castles such as Monmouth – changed hands several times as Royalist and Parliamentarian fortunes ebbed and flowed. More recently the Wye played a central role in the development of early tourism, when the growing interest in the picturesque led to the development in the 18th century of the Wye Tour, celebrating the outstanding landscapes of the lower valley.
The Wye rises high on the eastern flanks of Plynlimon (Pumlumon Fawr in Welsh), the highest peak in the Cambrian Mountains, and descends some 680m (2230ft) in travelling 250km (160 miles) to its confluence with the Severn south of Chepstow. The catchment embraces several major tributaries – principally the Elan, Ithon, Irfon, Llynfi, Lugg and Monnow. But these are just the dry facts: the excitement of the Wye Valley, especially for the walker, lies in the astonishing variety of landscape experiences to be savoured as the river and the valley repeatedly reinvent themselves on the way from mountain to sea.
At first the Wye has all the characteristics of a mountain stream, yet within a few miles it masquerades as a mature, tree-lined river flowing in a wide, shallow valley past Llangurig before reasserting itself as a fast-flowing upland river from north of Rhayader to Newbridge-on-Wye. Below Newbridge the widening river flows over a rocky bed in a valley that is steep-sided at times, especially where it squeezes between the rolling upland of Mynydd Epynt to the west and the surprisingly craggy Aberedw Rocks to the east. The hills crowd in around Hay-on-Wye too, although just upstream, at Glasbury, the valley is broad and the floodplain is lush meadowland.
Rapids on the Wye below Wyecliff (Walk 16)
Downstream from Hay the Wye, now an English river, assumes another character altogether, running languidly through the Herefordshire plain past riverside pastures and, increasingly, arable fields. South of Hereford a series of big, sweeping meanders creates narrow fingers of land that are almost cut off by the broad, sweeping river. This impression of indolence is deceptive, however, for the Wye is a spectacularly changeable and at times unpredictable river, with flooding common and at times dramatic – not least in the flat lands between Ross-on-Wye and Goodrich.
Having reached the lowlands the Wye ought to wander unhurriedly across a broadening floodplain to reach the sea. But this special river has one final, remarkable twist in its tale, entering an impressive gorge just below Ross-on-Wye and flowing between the steep, wooded valley sides that close in from Kerne Bridge onwards. Bare limestone cliffs rise abruptly from the river at Coldwell Rocks, Symonds Yat Rock and the Seven Sisters, and even at Chepstow, where the river is tidal and drifts sluggishly into the Severn Estuary, cliffs rise starkly from the river to guard Chepstow Castle.
Geology and landscape
Superficially, the geology of the Wye Valley is very simple – Silurian mudstones and siltstones dominate the upper reaches; the middle valley is largely underlain by Old Red Sandstone; and the lower Wye is primarily a product of Carboniferous limestone, although here as elsewhere there are substantial tracts of glacial and alluvial deposits masking the underlying geology.
The detail is, of course, much more complicated. At the head of the valley the broad Plynlimon massif is formed by an inlier of older Ordovician rocks within the Silurian outcrop that otherwise underlies the upper valley – including the great moorland plateau of Elenydd, which is often described as the ‘green desert’ of Wales. The vast emptiness of Elenydd, with its thick blanket of postglacial peat above the Silurian strata, rises above the Wye to the west, relieved only by the scattered conglomerate outcrops that form the highest summits, such as Drygarn Fawr with its spectacular summit cairns. This is Wales at its most elemental; a heavily dissected and eerily quiet grass, bilberry and heather moor.
The heather-clad slopes of Esgair Dderw, looking to Cerrig Gwalch and Moelfryn (Walk 28)
Some way downstream a tributary, the Ithon, hosts a remarkable landscape feature known as the Builth Inlier. The rugged topography here, with its low rocky hills, is a result of the intrusion of volcanic lavas and pyroclastic rocks into the surrounding mudstones. There are several locations between Llanelwedd and Llandegley where the rocks are exposed, sometimes with excellent fossils, and most remarkably of all it is still possible to identify an ancient shoreline with fossilised cliffs, sea stacks and beach deposits.