A ha-ha (French: hâ-hâ or saut de loup), 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 function of this ditch is usually to keep the animals away from the house. One could view the ha-ha simply as a wall that is integrated in its surroundings or as a device that inhibits a visible barrier between nature and mankind.