Dublin CastleHistoric castle in old Dublin with guided tours of the State Apartments, the medieval undercroft and the Chapel Royal. The cobbled upper yard and gardens are free to enter. free under 12
Malahide Castle Fairy Trail & Butterfly HouseA 30-minute DART ride from the city, with a fairy trail through old woodland, Ireland's only butterfly house, a large adventure playground and the Avoca cafe. Free under 3.