Caernarfon stands at the mouth of the River Seiont at the southwestern end of the Menai Strait. As the ancient British fortress of Caer Seiont, the Roman military station of Segontium and, from 1284 to 1586, the administrative centre of North Wales, the town has great historical associations. The superb castle, begun in 1283, is the largest of the great Edwardian Welsh defences. The walls enclose an area of about three acres and are up to nine feet thick in places with towers which reach to a height of 124 feet. It was at Caernarfon that Edward I proclaimed his eldest son Prince of Wales in 1301. This title has passed by tradition to the eldest son of each monarch since that time and in 1969 Prince Charles was created Prince of Wales here also. From the towers of Caernarfon Castle it is possible to look landwards to the maze of narrow streets which comprise the old town. On the seaward side, the castle rises dramatically from the busy harbour where the quay offers boat trips as well as excellent fishing.