That "Boxing Day (UK)" printed on your calendar"s December 26 square has nothing to do with the sport of boxing—although for many modern Brits, Aussies, and other denizens of the Commonwealth, the holiday"s full slate of TV sporting events is the main observance. Folks with enough post-holiday energy might even slide down the hills on the grounds of this historic estate-turned public park, Barnett Demesne, in Belfast, Northern Ireland.