Whilst this walk is not entirely in Monmouthshire, it starts in Tintern and just about follows the border with Gloucestershire. It is however a fantastic walk with the spectacular Tidenham Tunnel along the route.
Starting in centre of Tintern, Over the road from the Wild Hare you will see, Abby Mill, You will also see The Filling Station Cafe, which is a the ideal place to grab a takeaway drink for the walk.
Behind Abby Mill you will see the Wireworks Bridge over the Wye. Once you have crossed over the bridge you will join the five mile Wye Valley Greenways route.
The path is part of the disused Wye Valley Railway and links Tintern to Sedbury / Chepstow. The instructions for this walk are easy - follow the path! Along the way you'll enjoy beautiful views across the River Wye and also see remains of the old railway line that one transported trains up an down the valley.
After following the route for sometime you will come across the spectacular 1km Tidenham tunnel. Open during the daytime from 1 April to 30 September, this dimly light tunnel is an important local bat roost and visitors are asked not to add any additional lighting from torches or phones. Your eyes soon adjust to the lighting levels and you'll have great fun exploring this wonder of engineering. Outside of the tunnel opening times, an alternate route is signposted.
Out of the tunnel, it is just a short walk to the National Diving Centre. The NDC has a cafe and viewing platforms so you enjoy a view across the old quarry over a nice cup of tea and a cake. It is also the perfect place to rest your legs before the walk back towards Tintern.
Be warned, the route is open to walkers and cyclists so both need to be aware of the other.