FOLLY

noun (plural follies) Etymology: Middle English folie, from Anglo-French, from fol fool Date: 13th century lack of good sense or normal prudence and foresight, 2. criminally or tragically foolish actions or conduct, evil , wickedness , a foolish act or idea, an excessively costly or unprofitable undertaking, an often extravagant picturesque building erected to suit a fanciful taste