
thumb|Comparison of a ha-ha (top) and a regular wall (bottom). Both walls prevent access, but one does not block the view looking outward.
thumb|Comparison of a ha-ha (top) and a regular wall (bottom). Both walls prevent access, but one does not block the view looking outward.
A ha-ha ( or ), also known as a sunk fence, blind fence, ditch and fence, deer wall, or foss, is a recessed landscape design element that creates a vertical barrier (particularly on one side) while preserving an uninterrupted view of the landscape beyond from the other side. The name comes from viewers' surprise when seeing the construction.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).