A battery tower was a

defensive tower A fortified tower (also defensive tower or castle tower or, in context, just tower) is one of the defensive structures used in fortifications, such as castles, along with defensive walls such as curtain walls. Castle towers can have a variety of ...

built into the outermost defences of many

castle A castle is a type of fortification, fortified structure built during the Middle Ages predominantly by the nobility or royalty and by Military order (monastic society), military orders. Scholars usually consider a ''castle'' to be the private ...

s, usually in the 16th century or later, after the advent of

firearm A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originate ...

s. Its name is derived from the word

battery Battery or batterie most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source * Battery indicator, a device whic ...

, a group of several

cannon A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during th ...

. These, usually round, towers could house numerous cannon oriented in various directions and on several levels and their firepower was therefore clearly superior to that of any attackers who, at best, could only bring their cannon to bear on the main line of assault. The individual levels of battery towers are often connected by ramps so that the cannon could be arranged in various ways at the many

embrasure An embrasure (or crenel or crenelle; sometimes called gunhole in the domain of Age of Gunpowder, gunpowder-era architecture) is the opening in a battlement between two raised solid portions (merlons). Alternatively, an embrasure can be a sp ...

s. Where artillery towers were level with their adjacent walls they were called

roundels A roundel is a circular disc used as a symbol. The term is used in heraldry, but also commonly used to refer to a type of national insignia used on military aircraft, generally circular in shape and usually comprising concentric rings of differ ...

. There are battery towers at: *

Bentheim Castle Bentheim Castle () is an early medieval hill castle in Bad Bentheim, Lower Saxony, Germany. The castle is first mentioned in the 11th century under the name ''binithem''. Situation The castle is built on a protrusion of Bentheim sandstone, whi ...

Nanstein Castle Nanstein Castle () is a ruined medieval spur castle above the town of Landstuhl, Germany, which has been partially reconstructed. Built in the 12th century, the red sandstone rock castle was once owned by Franz von Sickingen who was mortally wo ...

Neudahn Castle The rock castle of Neudahn, in the southwestern Palatine Forest in the German state of Rhineland-Palatinate, is located at the northern end of an elongated ridge near the town of Dahn. The heart of the castle is situated on one of the sandstone r ...

* Burg Castle *

Calenberg Castle Calenberg Castle (, later called and ; ruins known as ) was a medieval lowland castle in central Germany, near Schulenburg in the borough of Pattensen, west of the city of Hildesheim. It was built as a water castle in 1292 by the House of Wel ...

Zwinger A () is an open kill zone area between two defensive walls that is used for defensive purposes. s were built in the medieval and early modern periods to improve the defence of castles and town walls. The term is usually left untranslated, ...

See also