The parish churchyard of St. Patrick's, Cairncastle, is of considerable historical interest. An old Spanish Chestnut tree which can be found there is said to have grown from a seed in the pocket of a sailor drowned off the coast during the time of the Spanish Armada in 1588; legend has it that his body was washed ashore and buried at Cairncastle. Other interesting graves in the cemetery include that of local clergyman and historian Rev. Classon Porter, who once lived at nearby Ballygally Castle and whose tombstone is in the shape of a Celtic Cross. Inside the church is a baptismal font once used by Dean Jonathan Swift, author of Gulliver's Travels.