At Home: A Short History of Private Life

by Bill Bryson

To maximize important prospects, Vanbrugh introduced another inspired feature—the folly, a building designed with no other purpose in mind than to complete a view and provide a happy spot for the wandering eye to settle. His Temple of the Four Winds at Castle Howard was the first of its type. To this he added the most ingenious and transformative innovation of all: the ha-ha. A ha-ha is a sunken fence, a kind of palisade designed to separate the private part of an estate from its working parts without the visual intrusion of a conventional fence or hedge. It was an idea adapted from French military fortifications (where Vanbrugh would have first encountered them during his years of imprisonment). Because they were unseen until the last instant, people tended to discover them with a startled cry of “Ha-ha!”—and hence, so it is said, the name. The ha-ha wasn’t simply a practical device for keeping cows off the lawn, but an entirely new way of perceiving the world. Grounds, garden, parkland, estate—all became part of a continuous whole.