Criccieth Castle (or Castell Cricieth in Welsh) is a Welsh castle situated on the headland between two beaches in Criccieth, Gwynedd, in North Wales, on a rocky peninsula overlooking Tremadog Bay.
The castle was built by Llywelyn the Great of the kingdom of Gwynedd, who created the immense gatehouse flanked by D-shaped stone towers. Later, his grandson Llywelyn ap Gruffudd – or Llywelyn the Last – added the outer ward, curtain walls and two new towers. Criccieth was heavily modified following its capture by English forces of Edward I in the late 13th century.
Although the stone castle was begun in the 1230s, there were three main building phases plus several periods of remodelling. It was still in English hands in 1404 when the towers were burnt red by Owain Glyndŵr. Without a garrison to protect it, the town became Welsh once more.