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40+ Fort and Castle Architecture Terms A–Z (With Pictures)

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Bled Castle, a medieval castle in Bled, Slovenia

Bled Castle, a medieval castle in Bled, Slovenia

Medieval Castle Architecture and Design Terminology A–Z

The Middle Ages, or the medieval period, was a fascinating period in human history filled with wonderous events: the fall of the Roman Empire, the founding of the first universities, numerous technological and cultural transformations, and the Black Death.

The architecture of the medieval period was marked by several distinctive styles, including Gothic, Renaissance, and French. Castles and forts were built for protection and were the primary secular architecture of the Middle Ages. In this article, you'll find an A–Z list of the most common terms used in medieval castle and fort architecture, along with photos.


An angstloch is usually located above the basement of a fighting tower or bergfried. The description of these basement rooms as "dungeons" stems from the castle studies of the 19th century.

No evidence indicates that prisoners were really lowered through the angstloch into the dungeon using a rope or rope ladder, as these 19th-century accounts suggest. Archaeological finds, by contrast, indicate the use of these basement spaces as storerooms.


An arrowslit (often referred to as an arrow loop, loophole, or loop hole, and sometimes a balistraria) is a narrow vertical aperture in a fortification through which an archer can launch arrows.


In fortifications, a bailey or ward refers to a courtyard enclosed by a curtain wall. In particular, an early type of European castle was known as a Motte-and-bailey. Castles can have more than one bailey. Their layout depends both on the local topography and the level of fortification technology employed, ranging from simple enclosures to elaborate concentric defenses.

In addition to the gradual evolution of more complex castle plans, there are also significant differences in regional traditions of military architecture regarding the subdivision into baileys. The bailey was a very useful fortification, and many castles used it.


The banquette refers to a continuous step built into the interior of the parapet, enabling the defenders to shoot over the top with small arms.


A barbican is a fortified outpost or gateway, such as an outer defense to a city or castle or any tower situated over a gate or bridge that was used for defensive purposes. Usually, barbicans were situated outside the main line of defenses and connected to the city walls with a walled road called the neck.


A bartizan, also called a guerite or échauguette, or spelled bartisan, is an overhanging, wall-mounted turret projecting from the walls of late medieval and early-modern fortifications from the early 14th century up to the 18th century.

Most frequently found at corners, they protected a warder and enabled him to see his surroundings. Bartizans generally are furnished with oillets or arrow slits. The turret was usually supported by stepped masonry corbels and could be round or square.


A bastion is a structure projecting outward from the curtain wall of a fortification, most commonly angular in shape and positioned at the corners. The fully developed bastion consists of two faces and two flanks with fire from the flanks being able to protect the curtain wall and also the adjacent bastions.


A battlement in defensive architecture, such as that of city walls or castles, comprises a parapet (i.e., a defensive low wall between chest-height and head-height), in which gaps or indentations, which are often rectangular, occur at intervals to allow for the launch of arrows or other projectiles from within the defenses.

These gaps are termed "crenels" (also known as carnels, embrasures, or wheelers), and the act of adding crenels to a previously unbroken parapet is termed crenellation.

Bent Entrance

A bent entrance is a defensive feature in medieval fortification. In a castle with a bent entrance, the gate passage is narrow and turns sharply. Its purpose is to slow down attackers attempting to rush the gate and impede the use of battering rams against doors.



In medieval fortresses, a bretèche or brattice is a small balcony with machicolations, usually built over a gate and sometimes in the corners of the fortress' wall, with the purpose of enabling defenders to shoot or throw objects at the attackers huddled under the wall.