In the UK you run across what are called "Follies". Strictly speaking they are structures that are not actual dwelling places, but are simply decorative touches. Fake Greek Temples, fake ruins, faux castles.
Driving in northern Wisconsin I was surprised to see this:
I can't tell from the road if this is an actual "castle" or just a house with an extended false front and some turrets.
Certainly odd. Possibly Folly.