Surrounding moat at the entrance of Cardiff Castle in Cardiff in Wales. Source: Roman Babakin/AdobeStock

9 Myths About Medieval Moats and the Truth Behind Them


Medieval moats have long been shrouded in mystery and misinformation, with tales of alligators and impenetrable walls. But the truth about these ancient structures is far more fascinating and complex. In this article, we'll dispel nine common myths about moats and delve into the diverse and dynamic history of these captivating architectural wonders. Get ready to embark on a journey through time as we uncover the truth about moats!

1.    Moats Were Purely for Defense

Let’s begin by putting an end to the most widely believed myth about moats - that they were ONLY a defensive feature. 

When we picture an old medieval castle in our head the likelihood is we imagine it with a big moat going around it with a draw bridge at the main gate. While it is true that moats offered some protection to castles, the truth is they were not just used for military defense.  

Moats were often used as a display of wealth and status which served as a symbol of the owner's prestige and power. The wider, the deeper, and the more extravagant the design, the more impressive it was. 

Famous European examples of this are the moat surrounding the Tower of London which was not only a defensive measure but also served as a symbol of the monarchy’s power, and the moat surrounding the Palace of Versailles, which was also used as a decorative feature to showcase the wealth and grandeur of France’s royal court

Moats also served as a psychological barrier and were used to intimidate potential attackers, servings as a visual reminder of the owner’s strength. For example, the moat surrounding the Forbidden City in Beijing was used to separate the emperor from the common people, acting as a symbol of the emperor’s power, prestige, and distance from those below him.

The moat in the Forbidden City of Beijing, used to separate the emperor from the common people.  (Haluk Comertel/ CC BY 3.0 )

Finally, moats could also serve a more practical everyday purpose. The moats that surrounded feudal Japanese castles were often used as a source of water for irrigation and as a means of flood control. Some European castles used their moats as part of their sewage systems , while others used them to transport goods from one part of the castle to the other. They were even used for recreational activities like fishing and boating.

2.    Moats Were Always Filled with Water

There’s a good chance that the castle we pictured for our first entry had a moat filled with water, but that’s another common misconception. In reality, moats could be either wet or dry, filled with water, or simply a ditch. 

The type of moat one went with depended on the location, purpose, and resources the builders had available. Good luck filling the moat of a fortification built in an arid environment. 

An example of a dry filled moat at Conwy Castle. In the past it was filled with rocks.  (MathKnight/ CC BY-SA 4.0 )

Typically, a wet moat was filled with water from a nearby river or stream while a dry moat could be filled with rocks, earth, or other materials to create an obstacle. A moat filled with sharp rocks could be just as effective as a wet moat at holding off the enemy.

For example, the moat surrounding Conwy castle in Wales was dry and filled with rocks and earth which created a formidable barrier. In March 1401 two rebels took the castle by disguising themselves as carpenters. The castle and its moat were so formidable the rebels managed to hold it for 3 months, only surrendering it as part of a peace deal. Likewise, the Chateau de Vincennes in France and the castle of Caernarfon in Wales both had dry ditch moats which proved very effective.

Dry moats were also easier to maintain. Keeping a moat filled with water was often difficult, especially during dry seasons or prolonged droughts. This made dry moats a practical alternative. This is probably why the moat surrounding the citadel of Aleppo in Syria was a dry ditch. 

3.    Moats Were Impenetrable

People often exaggerate how effective moats were. While moats were often successful, they could be overcome by using bridges, ladders, or even by simply filling them with dirt. 

Castles and fortresses that featured moats were built with drawbridges that could be raised and lowered to allow access to the main structure. While these were an obvious necessity during peacetime, they were a weak spot during times of siege. During a siege, any kind of revolt within the castle (for example as the result of supplies running low during a long siege) could lead to a rebel letting down the bridge and letting the attackers in. 

Ladders could also be used to circumvent a moat, especially smaller ones. For example, the Castle of Leeds’s moat didn’t save it in 1321 when the castle was captured by the forces of Edward II . Some sources state that ladders were used during the attack to bypass the moat.

Additionally, the shallow depth and soft ground surrounding some moats meant they could simply just be filled in with dirt, allowing attackers to cross the moat and breach the castle walls. This happened in the case of the moat surrounding the castle of Caernarfon in Wales.

The Moat of Caernarfon Castle. In the past this would have been filled with water. The moat did not extend all-round the castle as the sea provided a natural moat on the south and west side of the building. (Eric Jones/ CC BY-SA 2.0 )

Moats were not the be-all and end-all of castle defense. They were used in conjunction with other defenses such as fortified walls, towers, and gates to create a multi-layered defense. The moat was designed to slow down or deter attackers, not to provide absolute protection - there’s no such thing.

4.    Moats Were only Found in Europe

When we think of moats, we think of the fairy tale European medieval castle, but in reality, lots of cultures from throughout history and from across the world have used moats. Europeans weren’t the first to think of them.

Moats have been used in Japan, Africa, and the Middle East. They were also used in ancient times, the Greeks, Romans, and Chinese all made use of them. Japanese castles such as the Himeji Castle and Osaka Castle both had moats filled with water. Likewise in the Middle East moats were to protect cities, fortresses, and other forms of military architecture. Both the citadel of Aleppo in Syria and the citadel of Baghdad in Iraq had moats.

Citadel of Aleppo in Syria. ( saxlerb/AdobeStock)

In Africa, both the Zulu and Ashanti peoples used moats to protect their villages. Rather than just being used to protect some rich lord or king, Africans used moats to protect their entire community, not just the elite.

5.    Moats Were Home to Dangerous Creatures

Castles with moats are a popular staple of fantasy fiction and this has caused some people to confuse the features of fantasy castles with those of historical ones. This has led to the misconception that owners filled their moats with dangerous creatures such as alligators to deter attackers.

In reality, while some moats may have had fish and other aquatic life, it was not common practice to keep dangerous animals in them. This myth likely stems from popular depictions of fantasy castles in media. For most castles built in Europe, bringing in dangerous aquatic creatures like alligators would have been ridiculously expensive. Keeping them well-fed and healthy would also have been a nightmare, especially in winter. Plus, your moat would have to be full to the gills with creatures to deter even the smallest attack force. The purpose of a moat was to create a barrier that was difficult to cross. Filling it with dangerous animals would have added nothing. 

Described as a “bear moat” between its first and second courtyards. (Ptrantina/ CC BY-SA 3.0 )

There is however one exception to this rule. The Krumlov castle in the Czech Republic has what can be described as a “bear moat” between its first and second courtyards. Since 1707 the castle's inner moat has been home to bears. It is unknown if the practice started as a warning to potential intruders or as a status symbol.

6.    Moats Were Always Circular 

That moat we pictured way back for the first entry most likely had a circular moat. Look up a fantasy castle in any children’s picture book and there’s a good chance the moat is circular. But once again this wasn’t always true.

A moat could be any shape: circular, square, rectangular, or completely irregular. The shape of a moat was typically decided by the shape of the structure it was protecting and its surrounding landscape.

In Europe circular moats were popular as they offered a symmetrical and visually appealing design. The Tower of London, Windsor Castle, and Conwy Castle all have circular moats for this reason.

On the other hand, sometimes practicality trumped design. Square and rectangular moats were common features of fortifications built in areas where space was at a premium, for example in mountainous or rocky areas. The Citadel of Saladin in Cairo has a square moat and the fortifications of Carcassonne in France have a rectangular one.

The castle of Spissky in Slovakia has an irregular moat, still stunning in its form. (Michal Klajban, CC BY-SA 3.0 )

Moats could also be irregular in shape, either for aesthetic reasons or because the terrain made a regularly shaped moat too difficult to dig. The medieval castle of Spissky in Slovakia is one such castle with an irregular moat.

7.    Only Castles Had Moats

Just as we said earlier, people from throughout history and from across the globe have used moats. Historically if something was worth defending, there’s a good chance a moat was one of its defensive features.

The use of moats was not limited to castles but could be found in a variety of structures that needed more security. For example, palaces and other high-security buildings such as those used by royalty or government officials often had moats. The Palace of Knossos in Crete and the Alhambra Palace in Granada Spain both had moats that they used to offer their high-profile residents and guests extra security.

Military fortresses often also made good use of moats. The Fortress of Klis in Croatia and the Fortress of Rethymno in Greece both had moats that were used to give these important military strongholds added security.

Surrounded by a fortified wall, the 16th-century city of Shibam used this structure for protection. (Dan from Brussels/ CC BY-SA 2.0 )

Sometimes entire towns and cities used moats. As mentioned earlier it was a common practice of some African tribes to entrench their whole village with a moat. Likewise, the historic city of Shibam in Yemen, once a center of trade and commerce, had a moat around the city walls to protect against raiders.

8.    Moats were only built during the Middle Ages

As we’ve already touched on, most people are familiar with the use of moats during the Middle Ages, but a lot of people don’t realize how widespread their use has been throughout history.

If we look back to ancient times, the Greeks and Romans made use of moats, as did the Egyptians. For example, the Palace of Knossos in Crete had moats to protect from raiders and invaders. The castles of Feudal Japan, such as Himeji Castle also had moats. Even the Great Wall of China, built during the Ming Dynasty (1368-1644), incorporated moats in certain sections.

Nominated World Heritage site in 1993, the Himeji castle is a fine example of ancient castle and moat architecture. (Corpse Reviver/ CC BY 3.0 )

In fact, moats are still in use. Modern military bases and prisons, such as the ADX Florence Maximum security prison in Colorado, USA, and the Citadel, South Carolina’s military academy, both use moats.

Perhaps the weirdest example of a modern moat however is the one to be found at the Principality Stadium in Cardiff, Wales. This football stadium has a moat around its pitch to supply a barrier between the players and rowdy spectators!

9.    Moats Were Always Wide and Deep

It isn’t just the shape of a moat that could vary, so could its depth and width. We tend to think of moats as being as wide and deep as possible, but the truth is it depended on the individual moat's use.

For example, the moat at Himeji Castle in Japan was designed to be over 50 feet wide and over 20 feet deep. This made it an imposing barrier for any wannabe invaders. In contrast, the moat at the Palace of Knossos in Crete was much smaller, a few feet wide, and very shallow.

Moats were expensive and labor and time intensive to build. If there was a large perceived threat, then it was worth it to spend the extra time and money building a wide, deep moat that could realistically deter a large force. On the other hand, if all you needed was a moat that served as a psychological deterrent (for example to keep the commoners out), then a much smaller moat often did the trick. 


Despite the many myths and misconceptions surrounding moats, their impact on history is undeniable. Rather than the one-note defensive feature we so often read about in fantasy, moats were far more complex.

So, the next time you come across one of these fascinating structures, take a moment to appreciate their rich and multifaceted history. Moats are a great example of how sometimes fact is more interesting than fiction. Whether you're a history buff or just fascinated by medieval architecture, the moats of the past have much to offer, and we hope this article has given you a deeper understanding and appreciation for these remarkable structures. 

Top image: Surrounding moat at the entrance of Cardiff Castle in Cardiff in Wales. Source: Roman Babakin /AdobeStock

By Robbie Mitchell


Cartwright, M. 2019. Himeji Castle . Available at:

Editors. 2018. Moat. Available at:

Jarus, J. 2017. Knossos: Palace of the Minoans . Available at:

Lepage, J.G. 2012. British Fortifications Through the Reign of Richard III: an Illustrated History. Mcfarland.



Pete Wagner's picture

The idea of a nice place surrounded by water probably got its start in the earliest era of Atlantis (Richat Structure, aka Eye of Africa), probably initially designed to have only ONE concentric ring.  The idea proved good, and they expanded.

Nobody gets paid to tell the truth.

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