In everyday language, the word “folly” usually refers to a foolish action or object. But to an architectural historian, it has a more precise meaning: a folly in that sense is any decorative building that has little or no practical use.
True architectural follies are relatively rare in North America. (Building follies in the more general sense, of course—as exemplified by oversized, haphazardly insulated, and poorly air-sealed residential structures—are not uncommon at all.) But in much of Europe—and especially Great Britain and Ireland—there’s a long tradition of architectural follies. Wealthy estate owners in the 18th and 19th centuries were fond of stone follies that could be astonishingly large and elaborate. The Jealous Wall in County Westmeath, Ireland, for example, is a full three stories high and more than 150 feet long. At the other extreme, The Hermitage folly—near the English hamlet of Littlebeck—consists of just one stone.
In some instances, follies served as public works projects in a time before government relief programs for the poor. Ireland’s so-called “famine follies” were designed by prosperous landowners as a way to pay unemployed laborers to turn their hands to something without taking productive work away from those lucky enough to have it.