The castle's southeast tower leans at a 10-degree angle, caused by the foundations slipping during the Civil War.
The extensive moat system was designed to be flooded by diverting the Nant Gledyr stream to create an impenetrable water barrier.
The castle features a rare example of a 'brawn' or mechanical portcullis system which remains partially visible.
Its design was heavily influenced by the contemporary fortifications of the Crusader states in the Near East.
The site includes a reconstruction of a medieval siege engine, specifically a trebuchet, on the grounds.
It served as the primary set for various scenes in the television series 'Merlin' and 'Doctor Who'.
Caerphilly Castle is the largest castle in Wales and the second-largest in the United Kingdom, trailing only Windsor Castle. It features an extensive system of concentric walls and man-made lakes, representing a masterclass in 13th-century military engineering. Built by Gilbert de Clare between 1268 and 1271, the fortress was designed to secure territory during the conflict between the Normans and the Welsh princes. The structure is famously recognized for its leaning southeast tower, which tilts at a more dramatic angle than the Leaning Tower of Pisa. It was the first truly concentric castle in Britain, utilizing a 'walls within walls' defense system. The site currently serves as an active preservation project managed by Cadw. Visitors can explore the massive gatehouses, restored Great Hall, and the surrounding water defenses.
The lakeside path on the eastern side provides the most iconic reflection shot of the castle towers in the water.
Walk the entire perimeter path around the lakes for a clear view of the castle's scale and the iconic leaning tower.
Climb the narrow, original stone staircases to access the wall walks, but be prepared for low ceilings and steep steps.
Allow time to visit the Great Hall, which has been restored to reflect its original architectural grandeur.
Attempting to climb on the defensive walls or roped-off sections, as the stonework is delicate and dangerous.
Sturdy, non-slip footwear is essential due to uneven historic stone floors and steep stairs; keep to marked paths to protect site masonry.
