HA HA!

Added 1440954980 by Max Operandi.

A ha-ha (or ha-ha wall) is a recessed landscape design element that creates a vertical barrier while preserving views. The design includes a turfed incline which slopes downward to a sharply vertical face, typically a masonry retaining wall. Ha-has are used in landscape design to prevent access to a garden, for example by grazing livestock, without obstructing views. In security design, the element is used to deter vehicular access to a site while minimizing visual obstruction. The name "ha-ha" derives from the unexpected (i.e., amusing) moment of discovery when, on approach, the recessed wall suddenly becomes visible.