ablaq Middle Eastern tradition of architectural decoration combining different coloured stone

antemurabilus second or outer walls

ashlar stone cut into rectangular blocks and laid in regular rows

bailey, bailli fortified enclosure with a castle

barbican outer defensive enclosure, usually outside a gate

barrel vault vaulting in the form of an elongated arch

bastion projecting or additional part of a fortification

castrum (pl. castra) fortified enclosure, usually rectangular

chatelain commander of a castle

chemin de ronde raised walkway around the circuit or curtain-walls

concentric castle fortification with two or more circuit walls

corbel stone bracket to support another structure

crenellation tooth-like projections along the top of a fortified wall to provide protection for the defenders

cubit unclear unit of measure, about half a metre

curtain wall continuous defensive wall around a fortified location

donjon main tower of a fortified location, or a single isolated tower

double-castrum fortified enclosure with two concentric defensive walls

drawbridge entrance bridge, usually over a moat, which can be raised, usually blocking the gate behind

embossed masonry blocks of stone in which the centre is raised and usually roughly cut embrasure opening in a fortified wall through which the defenders can shoot

enceinte curtain-wall

forewalls additional defensive walls in front of the main defensive walls and towers

fosse defensive ditch

galleries passages, usually within a defensive wall, sometimes with embrasures

glacis smooth slope leading to the base of a fortified wall

hoarding wooden structure in the form of a gallery mounted on top of, and also ahead of, a defensive wall

keep main tower of a fortified position (see donjon)

machicolation overhanging structure on a tower or fortified wall

merlons raised masonry forming a crenellation (see above)

oat ditch or fosse forming an obstruction outside a defensive wall

motte and bailey castle consisting of a tower on a small man-made hill (motte), with an outer fortified enclosure (bailey)

portcullis grid-like gate or iron or iron and wood, usually raised an lower into position inside a gateway

posterns small doors or gates in the defences of a fortified position

redoubt outwork of a fortified place

salient towers towers thrust forwards from a fortified wall

slot machicolation aperture above a broad groove down the face of a tower or fortified wall

spur-castle castle built on a spur or promontory, usually on the side of a hill

talus additional sloping front along the lower part of a wall and tower

undercroft lowest chamber of a multi-storey building or structure

ward open area surrounded by a curtain wall

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