On my first trip to England in 1974 I headed straight for Broadway in the Cotswolds. This structure is often called England's Smallest Castle, but the Broadway Tower is really a folly. You can get a commanding view of the surrounding countryside from the top. photo ©Al Cooper
In architecture, a folly is a building constructed primarily for decoration, but either suggesting by its appearance some other purpose, or merely so extravagant that it transcends the normal range of garden ornaments or other class of building to which it belongs. In the original use of the word, these buildings had no other use, but from the 19th to 20th centuries the term was also applied to highly decorative buildings which had secondary practical functions such as housing, sheltering or business use.