Caerphilly Castle is an imposing medieval fortress mirrored in the waters of its placid lakes. It was built amid alarms and excursions by the lords of Glamorgan following their annexation of upland Senghenydd in 1267 and was completed by 1290. It was associated with a borough (NPRN 268017) and a vast deer park enclosing the Aber valley 3.0km to the north-west (NPRN 307764). The castle was in decline by the fifteenth century and it was ruinous by the earlier sixteenth. Nevertheless it was probably put into a state of defence in the mid seventeenth century when a great bastion or redoubt was raised to guard its north-western side (NPRN 300400). A major campaign of restoration and reconstruction was carried out in 1928-39. Since then the castle has been taken into state care and its lakes have been reflooded.

The castle consists of a great walled central court with tall round towers at each corner and huge twin-towered gatehouses on the east and west sides. Within is a magnificent earlier fourteenth century great hall and other grand apartments. The court is set within a concentric walled platform that rises from the waters of the lakes. These are held back by a massive fortified embankment on the east side that presents an unparalelled 280m long array of walls, towers and bastions towards the town. A corn mill is set within this area (NPRN 307852). There is a further walled platform on the west side of the castle.

Sources: RCAHMW Glamorgan Inventory III.1b The Later Castles (2000), 51-104
CADW Guide to Caerphilly Castle revised edition (1997)

John Wiles, RCAHMW, 5 February 2008

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Surrounded by two lakes, Caerphilly Castle is the largest castle site in Wales and the earliest example of a Norman fortification with a concentric design in Great Britain.

Although the Romans built an auxiliary fort here as early as 75 CE, it was abandoned again by the second century and for the next one thousand years, the site remained sparsely populated. In 1268, Gilbert de Clare, the Norman Marcher Lord of Glamorgan, commissioned the construction of the stone castle. Over the next three decades, the concentric castle and lakes were created, but with the death of Sir Gilbert in 1295, construction ceased almost completely. For a short period in 1326 the castle rose to prominence as the English king Edward II sought refuge here from his estranged wife, Queen Isabella, and her partner, Roger de Mortimer. In the fourteenth century, the castle passed into the hands of Richard Beauchamp, Earl of Worcester, but it was abandoned and fell into disrepair as he made Cardiff Castle his chief residence. In subsequent centuries, the decay of the castle was accelerated by the draining of the lakes and the removal of stone for the purpose of renovating Thomas Lewis's nearby house.

In the Romantic period, Caerphilly was frequently the first castle ruin tourists would encounter on their arrival in Wales as it is situated so close to the Welsh border with England. Like the Austrian count Gottfried von Purgstall, the size and spread of the castle reminded many travellers of the nearby situated ruins of Tintern Abbey. Much unlike its sacral cousin further east and most other ruined castles all over Wales, however, Caerphilly Castle was not covered in ivy and green vines.

Since 1844, the year of Carl Carus's disappointed visit to the ruins, which he found more desolate than beautiful, extensive conservation and restoration work has been carried out on the site. The lakes have been restored, tumbled down masonry has been put back into its original place and the Great Hall has been restored. Luckily for tourists today, the castle's most prominent feature, the great leaning tower, remains untouched as it was found stable enough to withstand the pull of gravity.

Record updated as part of the AHRC-funded project 'Journey to the Past: Wales in historic travel writing from France and Germany'.
R. Singer (Bangor University) and S. Fielding (RCAHMW), 2017.