“This section crosses the gently undulating and very peaceful farmland of Monmouthshire. Leaving behind the River Wye you are now joined by its tributaries, the rivers Monnow and Trothy. This area is mainly sheep country but on route you will also pass through orchards, now mainly supplying apples to the cider industry. The Dyke itself is nowhere to found along this section of the Trail but the area has a rich medieval history with ruined castles and abbey sites. The Trail passes right alongside White Castle, well worth a visit if you have an hour to spare, a Norman castle originally probably built by William Fitz Osbern and then greatly improved in the 13^th century by Hubert de Burgh. White Castle is one of 3 castles in the area, the others being Grosmont and Skenfrith, all three linked by the 16 mile Three Castles Walk.
The Trail also passes through the site of Abbey Grace Dieu. Founded in 1248 it was the last Cistercian house in Wales, nothing remains now except for a few grassy undulations. The route passes through the small villages of Llanfihangel Ystum Llywern, Llantilio Crosseny, White Castle and Llangattock Lingoed, all with churches that are well worth a brief visit. On the approach to Pandy there are great views of the Black Mountains including Hatterrall Ridge over which the next part of the Trail passes and Skirrid, sometimes known as Holy Mountain.” [https://www.nationaltrail.co.uk/offas-dyke-path/routes].