Local historical interest is concentrated on the 18th century Bishop of Derry’s ruined palace, the Mussenden Temple on the clifftop, and the Black Glen set within the Downhill Estate, which is now owned by the National Trust. The palace and estate were created by Frederick Hervey, 4th Earl of Bristol who was the Bishop of Derry in the 1780s.
The Mussenden Temple, with its precarious perch on the basalt cliff edge is one of the most photographed scenes in Ireland, and features in The Game of Thrones.
The 17th century Hezlett House is a thatched cottage with a cruck structure and is situated at the crossroads near the village. Built around 1691, it was originally a rectory or farmhouse. There is also an ancient tree adjacent crossroads.
The actor James Nesbitt lived in Castlerock as a teenager.
The village was also the holiday destination for the famous author C. S. Lewis. Born in Belfast, he holidayed in Castlerock as a child and took inspiration from Downhill House for some of his books including The Lion, the Witch and the Wardrobe.
Nansy Bryson, from Castlerock, was a passenger on the ill-fated MV Princess Victoria ferry which sank on the Stranraer to Larne route in heavy seas on 31 January 1953 with the loss of 133 passengers. A missionary, she had been at a meeting in Scotland and was returning home when the ship started to flounder. Survivors described how she helped children into lifeboats and sang hymns before being swept into the sea herself where she drowned. She has been described as the “heroine of the Princess Victoria”.