Now famous for its leaning tower, in its time it was a revolutionary castle design

Caerphilly Castle was begun in 1268 by one of Henry III's most powerful and ambitious barons, Gilbert de Clare, to prevent lowland south Wales from falling into the hands of the Welsh leader Llywelyn the Last, who controlled most of mid and north Wales. The largest medieval fortress in Britain after Windsor, it can also claim to be one of the great medieval castles of western Europe.

At the time of its building in the late 13th Century, it was a revolutionary masterpiece of military planning. Concentrically built, the rings of stone and water defences are formidable even today. The castle's active history was an extremely short one. By 1283 Edward I had effectively removed the threat of Welsh independence and minor Welsh attacks thereafter made little impact.

Famous now for its 'leaning tower', the castle also boasts an impressive great hall which is still in use today.