To last; to endure; to remain unimpaired.

That which keeps or protects; a stronghold; a fortress; a castle; specifically, the strongest and securest part of a castle, often used as a place of residence by the lord of the castle, especially during a siege; the dungeon. See Illust. of Castle.

The strongest tower of a castle.

The main tower of a castle, usually free-standing. (Kenyon, John R. Medieval Fortifications, 211) Strong central tower within outer walls of castle. (Frame, Robin. Colonial Ireland, 1169-1369, 144) Strong tower within the walls of a castle, used to make a last stand when all other parts of the castle defences had fallen. (Wise, Terence. Medieval Warfare, 249) Related terms: Castle / Donjon / Keep, Tower / Keep, Shell / Keep, Hall

the strongest and securest part of a medieval castle, often a tower.

The major tower of a fortification, often acting as its last defence. RCHME. Clifford's Tower was built in the medieval period as the keep of York Castle.

See Donjon

A strong stone tower; main tower; donjon; stronghold.

the main tower within the walls of a medieval castle or fortress

a building common to many forms of castle

a place from the medieval days that kept families safe from those that would bring harm

a small castle

a tower in which soldiers stand and shoot approaching attackers

central tower of a Norman castle.

the principal tower of a castle, usually in the centre. Donjon, not to be confused with dungeon, is the French term for keep.

The innermost central tower of a medieval castle which served both as a last defense and as a dungeon and which contained living quarters, a prison, and sometimes a chapel; or a tower-like fortress, square polygonal or round, generally built on a mound as a military outpost.

A strong stone tower; the most heavily fortified part of a castle.

The last defensible position of a castle.

A central tower to a Medieval 11th to 13th century castle, when a curtain wall encloses the remainder of the site. This may be of an irregular shape or square. It may be surrounded by other buildings and be on top of a motte and bailey.

a blockhouse or redoubt built within a larger fort for use as a place of final refuge or last-resort defense.  Also called a citadel or cavalier.

Usually the highest innermost tower, often built to overlook and thus strengthen the most vulnerable sectors of the castle's defenses. It was also the point from which the commander might direct the defense.

Donjon; The defendable central part of a Norman castle. Either a Hall-keep with living quaters or a Shell-keep with open centre and walls with a sentry-walk

Donjon Main tower; final defensive refuge

A keep is a strong central tower which normally forms the heart of a castle. Often the keep is the most defended area of a castle, and as such may form the main habitation area, or contain important stores such as the armoury or the main well. An earlier word for a keep, still used for some medieval monuments, especially in France is donjon.