A garden folly is something that is placed/constructed in a garden to cause the viewer to pause. It’s an architectural feature of a garden. I think “gazebo.” Then, think far more creatively. We saw a whole bunch. Why folly? It ain’t a “show.” Who knows? That’s what they call ‘em. If I had more time, I’d consider lounging about for a spell.
Yes, this castle-like structure was built as a garden folly. Go figure. You can climb it. It was designed with a wide stair to allow people to climb and descend easily.