As funny as their name may sound, ha-has, otherwise known as ha-ha walls, deer walls or sunken walls, play an important role in landscape architecture. 

Once a common feature of 18th Century English gardens, they were originally used as a way to segment different areas of a landscape without spoiling the wider view. Now, they are a widely established feature of modern landscape architecture. 

This comprehensive guide will provide an in-depth look at what the definition for a ha-ha is, how they are used, and where the name ha-ha originates from. It’s perfect for anyone who is interested in landscape architecture, garden features or simply gardening in general.

What is a ha-ha in landscape architecture?

In architecture, a ha-ha is a type of garden design feature that forms a vertical barrier, separating one landscaped area from another. Ha-ha walls are typically sunken and built into a decline so that they can not be seen from surface level unless up close. This allows the garden to maintain a continuous, open view from a distance. 

In most cases, ha-has are constructed first by digging a substantial, dry ditch. Using dry-stone or brick walls, the inner side of the ditch is then raised to the same elevation as the surroundings. The ditch’s outside edge then typically rises sharply before levelling off onto turf. 

Despite their connections to English landscape design, the first ha-has were developed in France in the 18th Century. This design was then adopted by English landowners, who had already developed similar ‘deer-leap’ structures into their designs as early as the Norman conquest.

Although ha-has are still in evidence in gardens around the world, alternative methods of fencing and barriers are typically used in modern landscaping. 

Why are ha-has used in gardens?

The overriding purpose of ha-has in gardens is generally to permit the division of various landscaped areas while preserving a clear, unobstructed perspective. However, that doesn’t explain why land owners would want their gardens divided in the first place. 

The answer for this lies in the fact that, in earlier times, animals like sheep and cattle were employed to keep grassland trimmed. Due to this, a ha-ha was commonly built to separate the estate’s gardens and grounds from the grazing area. 

And, while other types of division, such as a trench, may have kept the animals out, they may also develop into a moat or become overgrown. A ha-ha prevented this and kept the estate’s grounds immaculate by permitting livestock to graze right up to the barrier.

Of course, a natural benefit of this is that landowners were able to use ha-has as a defensive measure to keep intruders and trespassers away from the main building. Or, alternatively, to keep people in, should the building in question be a secure facility like a prison or asylum.

However, in modern times, technological advancements in home security have rendered the need for ha-has as a defensive measure largely redundant. 

Where did the name “ha-ha” originate from?

The name ‘ha-ha’ in popular terminology originates from early 18th Century France, when the landscape feature was first described as such in the book La Theorie et la Practique du Jardinage by author Dezallier d’Argenville. 

It is thought that he described the feature as a ‘ha-ha’ owing to the effect that greets viewers as they approach it. In essence, the optical illusion of a seemingly level landscape that, on closer inspecion, is actually divided by high walls provided by hidden ditches provokes the reaction of ‘ah ah’.

Since this first description, the phrase spread in popularity across Europe and North America. George Washington, in particular, called them ‘ha-haws’, while John Perceval, 1st Earl of Egmont is known to have also used the term in 1724. 

Where are ha-has usually found?

The most common place where you are likely to find historic placements of ha-has are in the surroundings of large country houses and estates, especially in England and France. Australia has also employed ha-has in some of their secure facilities, such as with Kew Asylum. 

They can also be found in North America and Canada, although examples there are few and far between. One such example is the Washington National Monument, whose management team introduced ha-has as a result of the increased need for security post-911. This is one of the most recent instances of new ha-ha construction. 

Some of the most well-known examples of ha-has around the world include:

  • The Washington National Monument, Washington D.C., USA
  • Beningbrough Hall, Yorkshire, England
  • Royal Artillery Barracks Field, London, England
  • Hameau de la Reine, Versailles, France
  • Kew Asylum, Melbourne, Australia

What is the difference between a ha-ha and a traditional fence?

The main difference between a ha-ha and a traditional fence is in the construction method and visual effect of the two features. Both ha-has and traditional fences are designed to obstruct and divide different areas, but the way they achieve this differs. 

On the one hand, a ha-ha separates parts of a landscaped area with the aid of a sunken ditch that leads to a wall, which rises to the same level of the rest of the turf. This creates an optical illusion of an uninterrupted view from a distance. 

On the other, a traditional fence is a vertical structure that rises from ground level. They are often made from wood or metal, and are a very visible barrier, and are designed that way to be obstructive to any intrusions. 

What is the difference between a ha-ha and a dry-stacked wall or terrace?

Although a dry-stacked wall or terrace and a ha-ha are both examples of landscape features, they have different functions and qualities.

For one, a ha-ha is a type of landscape element that divides a garden or park from adjacent property, like a field or pasture, while giving the impression of a continuous view.

Meanwhile, a dry-stacked wall or terrace is a kind of retaining wall that is constructed without the use of mortar. Typically, a dry-stacked wall or terrace is used to retain soil on a hillside, create level portions in a sloping environment, or both.

A ha-ha is supposed to be unseen or inconspicuous, but a dry-stacked wall or terrace is visible and intended to form a physical barrier or structure to hold earth or create level area. This is the primary difference between a ha-ha and a dry-stacked wall or terrace.

That’s it for our guide to the ha-ha. Whatever you call them, there’s no doubt they are a landscape architecture feature that is worth seeking out, as rare as they may be. 

For more news, compilations and discussions from the world of urban construction and architecture, explore our selection of articles here.

Or, for similar guides featuring definitions and meanings of architecture-related terms within the building profession, take a look through our range of building wikis. They include an explanation of what in situ construction is!  

Last Updated on 19 January 2023 by Michael