The Wye Valley Greenway follows the old railway trackbed south from Tintern toward Chepstow, including the long Tidenham Tunnel when it is open in daylight season. It is one of the easiest ways to see the valley without climbing.
Use it for a short out-and-back walk or as part of a longer day between river, woodland, and abbey. Check tunnel opening dates before making that the centre of the plan, as bat protection affects access.