 Raglan Castle ( Welsh : Castell Rhaglan ) is a late medieval castle located just north of the village of Raglan in the county of Monmouthshire in south east Wales . The modern castle dates from between the 15th and early 17th @-@ centuries , when the successive ruling families of the Herberts and the Somersets created a luxurious , fortified castle , complete with a large hexagonal keep , known as the Great Tower or the Yellow Tower of Gwent . Surrounded by parkland , water gardens and terraces , the castle was considered by contemporaries to be the equal of any other in England or Wales . During the English Civil War the castle was held on behalf of Charles I and was taken by Parliamentary forces in 1646 . In the aftermath , the castle was slighted , or deliberately put beyond military use ; after the restoration of Charles II , the Somersets declined to restore the castle . Raglan Castle became first a source of local building materials , then a romantic ruin , and is now a modern tourist attraction . 
