Ruthin Castle Ruthin Castle (Welsh: Castell Rhuthun) is a medieval castle in Wales, near the town of Ruthin (Rhuthun) in the Vale of Clwyd (Dyffryn Clwyd). It is built on a red sandstone ridge 100 feet above the valley and occupies a site that was first used as an Iron Age fort. Its location was of strategic importance as it overlooks an important river crossing. The castle was constructed in 1277 by Prince Dafydd ap Gruffydd, although there might have been an existing fortification on the site. It was known when built as Castell Coch yn yr Gwernfor (the red castle in the great marsh). A number of alterations were made to the castle over the centuries, but just prior to the Civil War its was reported to be in a bad state of repair. At which point it was again seen to be of strategic importance and had some work undertaken on it. However, during that war it was subject to an eleven week siege and sustained considerable damage from artillery attack. At the end of hostilities, Ruthin Castle was seen to pose a potential threat if it should fall into the hands of hostile forces. So in 1648 the castle was partially dismantled. Timber and stone from the castle was taken for use elsewhere. Part of the ancient walls still remain and now form part of a new building on the site.
In 1826, Ruthin Castle was purchased by a wealthy family. New buildings were erected and repairs were undertaken to the medieval castle ruins. Work was undertaken on the gardens and grounds. Further alterations to the buildings were made as the century progressed. The Castle was sold in 1923 and was turned into a private clinic for the investigation and treatment of medical diseases, but was subsequently closed around 1950. In the early 1960’s The Castle was purchased at auction and converted into an hotel. It is now the Ruthin Castle Hotel and Spa.