Conwy Castle is a medieval fortification in Conwy, on the north coast of Wales. It was built by Edward I, during his conquest of Wales, between 1283 and 1289. Constructed as part of a wider project to create the walled town of Conwy, the combined defences cost around £15,000, a huge sum for the period. Over the next few centuries, the castle played an important part in several wars. It withstood the siege of Madog ap Llywelyn in the winter of 1294–95, acted as a temporary haven for Richard II in 1399 and was held for several months by forces loyal to Owain Glyndŵr in 1401.
Following the outbreak of the English Civil War in 1642, the castle was held by forces loyal to Charles I, holding out until 1646 when it surrendered to the Parliamentary armies. In the aftermath the castle was partially slighted by Parliament to prevent it being used in any further revolt, and was finally completely ruined in 1665 when its remaining iron and lead was stripped and sold off. Conwy Castle became an attractive destination for painters in the late 18th and early 19th centuries. Visitor numbers grew and initial restoration work was carried out in the second half of the 19th century. In the 21st century the ruined castle is managed by Cadw as a tourist attraction.
UNESCO considers Conwy to be one of "the finest examples of late 13th century and early 14th century military architecture in Europe", and it is classed as a World Heritage site. The rectangular castle is built from local and imported stone and occupies a coastal ridge, originally overlooking an important crossing point over the River Conwy. Divided into an Inner and an Outer Ward, it is defended by eight large towers and two barbicans, with a postern gate leading down to the river, allowing the castle to be resupplied from the sea.
It retains the earliest surviving stone machicolations in Britain and what historian Jeremy Ashbee has described as the "best preserved suite of medieval private royal chambers in England and Wales". In keeping with other Edwardian castles in North Wales, the architecture of Conwy has close to links to that found in the kingdom of Savoy during the same period, an influence probably derived from the Savoy origins of the main architect, James of Saint George.
Before the English construction of the town of Conwy, the site was occupied by Aberconwy Abbey, a Cistercian monastery favoured by the Welsh princes. The site also controlled an important crossing point over the River Conwy between the coastal and inland areas of North Wales, and was defended for many years by Deganwy Castle. By the end of the 18th century, the ruins were considered picturesque and sublime, attracting visitors and artists, and paintings of the castle were made by Thomas Girtin, Moses Griffith, Julius Caesar Ibbetson, Paul Sandby and J. M. W. Turner. Several bridges were built across the River Conwy to linking the town and Llandudno during the 19th century, including a road bridge in 1826 and a rail bridge in 1848.
These improved communication links with the castle and further increased tourist numbers. In 1865 Conwy Castle passed from the Holland family, who had leased it from the descendants of the Conways, to the civic leadership of Conwy town. Restoration work on the ruins then began, including the reconstruction of the damaged Bakehouse tower. In 1953 the castle was leased to the Ministry of Works and Arnold Taylor undertook a wide range of repairs and extensive research into the castle's history. An additional road bridge was built to the castle in 1958. Already protected as a scheduled monument, in 1986 it was also declared part of the World Heritage Site of the "Castles and Town Walls of King Edward in Gwynedd".
UNESCO considers Conwy Castle one of "the finest examples of late 13th century and early 14th century military architecture in Europe". It hugs a rocky coastal ridge of grey sand- and limestone, and much of the stone from the castle is largely taken from the ridge itself, probably when the site was first cleared. The local stone was not of sufficient quality to be used for carving, however, and accordingly sandstone was brought in from the Creuddyn peninsula, Chester and the Wirral. This sandstone was more colourful than the local grey stone, and was probably deliberately chosen for its appearance.
The castle has a rectangular plan and is divided into an Inner and Outer Ward, with four large, 70-foot (21 m) tall towers on each side; originally the castle would have been white-washed using a lime render. The outside of the towers still have the putlog holes from their original construction, where timbers were inserted to create a spiralling ramp for the builders. Although now somewhat decayed, the battlements originally sported triple finial designs and featured a sequence of square holes running along the outside of the walls. It is uncertain what these holes were used for - they may have been drainage holes, supports for defensive hoarding or for displaying ornamental shields.