Ha-ha

A Ha-ha is a feature used in landscape garden design to keep grazing livestock out of a garden whilst providing an uninterrupted view from within. The feature consists of a turfed ditch, one side of which is sloping and the other vertical and faced with stone. Before the advent of mechanical lawnmowers a commonly used way to keep large areas of grassland trimmed was to allow livestock, usually sheep, to graze the grass. A ha-ha prevented the grazing animals on large estates from gaining access to the lawn and gardens adjoining the house, giving a continuous vista to create the illusion that the garden and landscape were one and undivided. The name "ha-ha" was given to the feature because, when walking towards it from the garden, it would only become apparent to the observer when in close proximity to it.