For millions of people in the English-speaking world, the now standard image of the British country house is Brideshead Castle in Wiltshire: the domed and doomed baroque country seat of the Marchmain family seen in the BBC adaptation of Evelyn Waugh's novel, Brideshead Revisited. In real life, the house used for the television series is Castle Howard, one of the largest and most opulent private homes in England, located on 10,000 acres of gardens, parkland, and woods in North Yorkshire, now visited by more than 200,000 tourists a year.
Between 3,500 and 4,000 country...