Caernarfon Castle The site of this castle was first fortified by the Norman Earl of Chester in 1090, but was soon recovered by the Princes of Gwynedd who held it until the defeat of Llywelyn Ap Gruffydd by King Edward I in 1282. The existing castle was begun in 1283 and finished about 1330. It is in the care of the Ministry of Works. The entrance is through the King's Gate on the north side of the castle. Entrance [----->