The Wye Valley Walk begins at Chepstow Castle and follows the river upstream through the Wye Valley Area of Outstanding Natural Beauty, passing Tintern Abbey before heading into Herefordshire and eventually to the river's source in mid-Wales. The full route is 136 miles, but the section from Chepstow to Monmouth — roughly 17 miles — is the most dramatic and frequently walked stretch, with the river cutting through a deep wooded limestone gorge that feels far wilder than its proximity to the M4 would suggest.
From Chepstow, the walk climbs above the gorge on the Welsh bank with views back over the castle and the railway bridge, then descends to river level at intervals where the gorge widens. The going is moderate rather than strenuous; the main challenge is the repeated climbs in and out of the gorge itself. Tintern Abbey comes into view from above before you descend to it — a moment that gives some sense of why the valley attracted Romantic painters and poets. The walk is clearly waymarked throughout and can be tackled in sections using the regular bus service between Chepstow, Tintern, and Monmouth on the B4293.