This 18th-century castle is best known within Ireland for the open-air rock and pop concerts held here in the summertime. For tourists, the big draw is the building itself, a Gothic Revival structure by James Wyatt. The design of the building was made grander in the early 19th century in advance of a visit by the English King George IV to Lady Conyngham, who is believed to have been his mistress (in fact, the Irish claim that the road from Dublin to Slane was built to ease George's journeys to her home). A fire in 1991 burned most of the castle's extensive collection of art and antiques. After extensive renovations, the castle is now open again for visits.