Skenfrith Castle is one of the Three Castles of Gwent, with Grosmont and White Castle, a chain of Norman strongholds guarding the border country between the River Wye and the Black Mountains and a main route from England into Wales. The ruin seen today is the early 13th-century rebuilding by Hubert de Burgh, a curtain wall with round corner towers around a circular keep on its earthen mound, beside the River Monnow and next to St Bridget's Church. Owned by the National Trust and cared for by Cadw, it is free to enter, with grass inside the walls for picnics and a river bank where children and dogs paddle. Reviewers describe a quiet spot where the church and riverside walks round out a short visit, and many take in the other two castles in a day. Tips from visitors: parking beside the castle is free but small, and there are no facilities, so bring a picnic.