Merlin's Cave

Harry spends his holiday with Maureen in Tintagel. Maureen takes him to Tintagel Castle, the place where the legendary King Arthur is said to have been born. However, she does not take him to the ruins, which are visited by all the tourists, but to a cave that completely submerged at high tide. According to legend, Merlin used to live here. When Harry explores the cave, he is surprised to discover a lot of dark numbers on the ceiling.