Secrets of Medieval Castles: Why Castle Stairwells Are Built Clockwise–There’s a Very Important Reason

Secrets of Medieval Castles: Why Castle Stairwells Are Built Clockwise–There’s a Very Important Reason
(Illustration - Shutterstock)
Michael Wing

Medieval castles were the central institutions of political power in the middle ages (a period of roughly 1,000 years between the 5th and 15th centuries), no less symbolic than the White House of modern-day America. The fascinating history of castles takes us right back to the roots of Western civilization.

The medieval world was structured much differently than in today’s nation states. Kings, lords, and knights ruled over lands, rented and farmed by peasants, who payed taxes in return for protection.

Illustration - Shutterstock | <a href="">zawisak</a>
Illustration - Shutterstock | zawisak

Rulers often lived in castles that would serve both as dwellings and fortifications from enemies. Effective defensive structures evolved over the centuries, from fenced, wooden forts atop a hill, surrounded by a moat and earthworks, to elaborate stone-walled structures consisting of concentric defenses: earthworks, moat, outer and inner walls, defensive fortifications, gates, keep, and much more.

Every detail of the structure was fine-tuned to provide the most effective defense against an invading army, maximizing advantages for the defenders and posing a multiplicity of dangers for attackers.

Yet, such intricacies and details are some of the most fascinating parts of these architectural monuments to our heritage. Outdated though they may be, they reveal insight into how mankind once fit into a world much different from our own today.

Here are just a few examples of such architectural aspects of medieval castles:

The Moat

Essential to castle fortifications, the moat consists of an artificially dug ditch that is then filled with water. In addition to making it harder for armies and siege machines to reach the walls, the moat’s primary function was to prevent attackers from digging tunnels under the castle walls. The purpose of that would be to undermine the wall’s foundation and have part of it collapse. This would allow enemies to breach an opening. With the moat in place, any attempts at excavation would be thwarted by water pouring in.
Illustration - Shutterstock | <a href="">Gail Johnson</a>
Illustration - Shutterstock | Gail Johnson
The natural lay of the land was a factor when choosing the site of a castle, and the placement of a moat would have played into that decision. The dirt and rock excavated during construction of the moat could be used to create a mound in the center upon which the castle would be built. The moat depth needed to be no more than a half-meter in order to impede attackers, and moats were sometimes studded with stakes to make them even more difficult to cross.

Curtain Walls and Keep

Stone walls presented a formidable defense against an attacking army. Like other aspects of castles, they evolved over the course of centuries. They are typically around 2.5 meters in thickness, sometimes housing passageways through them. And they consist of an exterior of dressed stone filled with a rubble and mortar core.

Castle walls are built on a foundation wider than the wall, consisting of rammed stone and rubble, or atop piles of oakwood driven into the soil, alternately. They were sometimes built upon a sloped plinth, which would make scaling more difficult. This eventually evolved into an angled, stone “curtain” at the base of the wall. This had an added advantage of causing rocks thrown from above to bounce toward the attacker in unpredictable directions.

Illustration - Shutterstock | <a href="">trabantos</a>
Illustration - Shutterstock | trabantos

Battlements atop walls, facing outward, allowed archers to take cover and fire at the enemy through narrow slits. There are no battlements on the inner side of the wall, as they could then be used by the enemy to fire inward, should the wall be breached. They would thus be left exposed to the subsequent stage of defense.

As castle designs evolved, a second, inner wall was added, providing yet another layer of defense. The inner wall was built higher than the outer wall, making the enemy even more vulnerable should they gain access. Sometimes there were underground tunnels connecting both walls, which would allow defenders an escape route, or even a sally port to cut the enemy off from behind.

A tower keep was the last place of defense in some castles. It was also the strongest building, consisting of thicker walls and a fortified entrance. As keeps were expensive to build, they were gradually replaced by larger, round towers along the castle wall.


Entrances present a logical target for an attacker, and that is why castles evolved, gradually placing their heaviest fortifications at these posts. Gates eventually came to be considered strong points rather than weak points. By the end of the 12th century, gatehouses consisted of two towers on either side of a recessed entrance. A heavy wooden door plus a metal and wood portcullis protected the gateway. Often, a drawbridge between the gatehouse and moat could be lifted with chains preventing easy access.

Above the gateway, fortifications include “murder holes” through which defenders could drop rocks, boiling water, or searing hot oil on attackers from above. They would also be able to douse any fires set upon the gates themselves.

Illustration - <a href="">Geograph</a>
Illustration - Geograph


Even minute details of castles are exploited to render every strategic advantage for the defender. Round spiral staircases of castles conspicuously all travel in a clockwise direction. Yet, there is a strategic reason for this: Assuming an attack will advance from below, a clockwise stairwell will position the attacker’s right hand (their sword hand) on the inside of the spiral, making swinging their weapon far more difficult. Meanwhile, defenders’ sword hands would be on the outside of the spiral, allowing freer use of their weapons and more protection.
Illustration - Pixabay | <a href="">stheaker </a>
Illustration - Pixabay | stheaker


No detail was neglected in the defenses of castles, including using the washroom. Toilets were devised to be as simple as possible: very often no more than simple wooden benches with a hole in it; positioned on top of the walls, waste would fall directly into the moat outside. Urinals were also set into some tower walls so that defenders would not have to leave their posts for long when nature called.
Illustration - Shutterstock | <a href="">Gail Johnson</a>
Illustration - Shutterstock | Gail Johnson
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