Tintagel Castle is situated adjacent to which body of water?

Tintagel Castle (Cornish: Dintagel) is a medieval fortification located on the peninsula of Tintagel Island adjacent to the village of Tintagel (Trevena), North Cornwall in the United Kingdom and is bordered by the Atlantic ocean.

It was settled during the early medieval period, when it was probably one of the seasonal residences of the regional king of Dumnonia. A castle was built on the site by Richard, 1st Earl of Cornwall in the 13th century, during the High Middle Ages. It later fell into disrepair and ruin.

The castle has a long association with legends related to King Arthur. This was first recorded in the 12th century when Geoffrey of Monmouth described Tintagel as the place of Arthur's conception in his mythological account of British history, 'Historia Regum Britanniae'. Geoffrey told the story that Arthur's father, King Uther Pendragon, was disguised by Merlin's sorcery to look like Gorlois, Duke of Cornwall, the husband of Igraine, Arthur's mother.

Tintagel Castle has been a tourist destination since the mid-19th century. Owned by Charles, Prince of Wales as part of the landholdings of the Duchy of Cornwall, the site is managed by English Heritage.