Tintagel Castle steps. The legendary site of King Arthur’s conception is Tintagel Castle. Excavations demonstrated that, as the legends said, this was a fortified home of the ruler of Cornwall in about 500AD. The largest fortified site of the ‘Arthurian’ period, it contained unprecedented remains of luxury goods from the Eastern Roman Empire. In 1998, a slate engraved with the name ‘Artognou’ and other names from the legends was discovered there.