The dramatic ruins of Tintagel Castle perch precariously on the clifftop above a thundering sea. Below, at low tide, it is possible to enter Merlin's Cave - for Tintagel is most famously associated with the legend of King Arthur and, according to 12th century writer Geoffrey of Monmouth, was Arthur's place of magical conception and birth. The castle actually dates from the 13th century and there is no hard evidence that it was ever associated with the legendary king. However, Tintagel is thought to have been some sort of power-centre during the Dark Ages, when Arthur may have lived. It's a great place to visit anyway - though it should be emphasised that the castle is in a highly ruinous state.