Little remains of this once strategically important castle and birthplace of Battle of Agincourt victor, Henry V. It was founded by William fitz Osbern shortly after the Norman conquest in the late 11th century. Built to guard crossing points of the Wye and Monnow rivers, it later passed to the Earl of Lancaster, one of Henry III’s sons. He added the Hall next to the Great Tower, which are the only surviving ruins. This was used for court sessions up until the 17th century. The castle changed hands three times during the English Civil War and was eventually slighted. 

The Great Castle House (background) is the headquarters of the Royal Monmouthshire Royal Engineers, which was built using stones from a Round Tower that once stood on the same site.