Castell y Bere Castell y Bere is a native Welsh castle near Llanfihangel - y - pennant in Gwynedd , Wales . Constructed by Llywelyn the Great in the 1220s , the stone castle was intended to maintain his authority over the local people and to defend the south - west part of the princedom of Gwynedd . In 1282 war with Edward I of England resulted in the death of Llywelyn ' s grandson , Llywelyn the Last , and Castell y Bere fell to English forces . Edward I expanded the castle further and established a small town beside it . In 1294 the Welsh leader Madoc ap Llywelyn mounted a major revolt and the castle was besieged and apparently burnt . Edward did not repair it and it became ruined . Today it is in the hands of Cadw and operated as a tourist attraction . History . 1220 - 40 . Castell y Bere Castle was built in the 1220s by Llywelyn the Great on a rocky hillock overlooking the Dysynni Valley , near Llanfihangel - y - pennant . Traditionally the Welsh princes had not constructed castles , instead using undefended palaces called " ilysoedd " , or courts . From the late 11th century onwards , the Normans had advanced into Wales , taking lands in the north and establishing a band of occupied territory in the south called the Welsh Marches . During the 12th century some timber and earthwork castles began to be built , but in small numbers . Llywelyn the Great initially controlled the princedom of Gwynedd , but grew more powerful over the course of his reign , extending his influence over much of Wales during the early years of the 13th century . Llywelyn was faced by several challenges , including dealing with the threat from the kings of England , and maintaining his authority over the native Welsh . In 1221 Llwelyn took control of neighbouring Meirionnydd from his son , Gruffydd ; Llywelyn had previously placed Gruffydd in power there , but the father and son had fallen out . The prince then began to build the castle of Castell y Bere with the intent of controlling the local population and securing his new south - west border , which included the mountain trade routes between Gwynedd , Powys Wenwynwyn and Deheubarth . Castell y Bere was the first of several stone castles built by Llewelyn and the initial castle consisted of several towers positioned around a courtyard , situated on a rocky hillock in the Dysynni Valley near Cadair Idris . 1240 - 1300 . Following Llwelyn ' s death in 1240 , Gwynedd ' s power declined and many of its eastern lands were taken by Henry III of England in 1247 . Llwelyn ' s grandson , Llywelyn the Last , took power in 1255 and imprisoned his brother Owain ap Gruffudd before extending his power across Wales . Llweyln extended the castle with an additional tower to the south , similar to that built at Dolforwyn , probably in order to provide additional accommodation . The conflict between the Welsh princes and the English kings continued in the reign Edward I . In 1282 Llweyln fought a final campaign against Edward , ending in the prince ' s death near Builth that December . His brother , Dafydd ap Gruffydd , assumed power but during 1283 was forced south into Snowdonia . Meanwhile , forces under the command of Roger Lestrange and William de Valence marched from south Wales and Shropshire , placing Castell y Bere under siege and taking it on 25 April . Edward deployed 7 , 000 troops to detain Dafydd who was finally captured and executed in October . A team of five masons and five carpenters , under the command of Master Bertram the Engineer , were left at Castell y Bere to conduct unspecified work after the English army had left . Edward continued to invest money and time in Castell y Bere ; he visited three times in 1284 , establishing a small town alongside the castle , possibly just to the east . Walter of Huntercombe was appointed the constable of the castle by Edward in 1284 and spent £47 building a new chamber there , potentially for the king to use during visits . In 1294 , however , the Welsh leader Madoc ap Llywelyn mounted a major revolt across Wales . Richard Fitzalan , the Earl of Arundel , was ordered in mid - October to ensure that the castle was secure , but by late October the castle was under siege from Madoc ' s forces . Robert FitzWalter , the castle ' s constable , was sent to lead a relief expedition . The final fate of Castell y Bere is uncertain , but it was probably taken by Welsh forces in late 1294 and subsequently burnt . 14th - 21st century . Following the revolt Castell de Bere and the new English town were both abandoned . While the castle was well situated , unlike the other new coastal castles built by Edward I it could not be provisioned by sea and as a result did not fit well into his plan for controlling North Wales . After many years , the site was finally cleared of undergrowth in the 1850s , revealing more of the castle ' s remains , and the first archaeological investigations were carried out . In 1949 Charles Corbett , the owner of the ruins , placed them into the guardianship of the state . In the 21st century the site is in the care of Cadw and is protected as a scheduled monument and maintained as a tourist attraction . In the light of Welsh devolution and other political changes , the history of Castell y Bere and similar Welsh castles has become increasing prominent . In response , Cadw have noted that they intend to give an increased priority to communicating the history of these castles and the Welsh princes . Architecture . Today the ruins of Castell y Bere still stand on a rocky outcrop , with protective ditches cut into the stone on the south and east sides . The entrance to the castle lies on the west side , where the barbican , probably built by Edward I , contains two gatetowers , overlooking the stone steps approaching the inner gate . Through the barbican is the castle courtyard , containing a large well and the remains of several internal buildings of uncertain date . The north tower is an apsidal , or " D - shaped " , design that is characteristic of Welsh castles of the early 13th century . Originally it may have contained either a hall or a chapel . What is today the middle tower was originally the southernmost part of the defences , but now leads through the Edwardian ditch yard to the south tower , another apsidal design that once contained spacious accommodation . Both the apsidal towers lacked fireplaces in the main chambers , instead using central heaths to heat the rooms . Unusually for an early Welsh castle , there is evidence of decorative sculpture , including statues of soldiers , having been built into the castle , along with decorative floor tiles . Castell y Bere is the only castle , other than Criccieth , to display such features . Historian Lawrence Butler considers that the castle has delivered some of " some of the finest stone carving from thirteenth - century Wales " .