The

fortifications A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from La ...

of the former

East Prussia East Prussia was a Provinces of Prussia, province of the Kingdom of Prussia from 1772 to 1829 and again from 1878 (with the Kingdom itself being part of the German Empire from 1871); following World War I it formed part of the Weimar Republic's ...

n capital

Königsberg Königsberg (; ; ; ; ; ; , ) is the historic Germany, German and Prussian name of the city now called Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussians, Old Prussian settlement ''Twangste'' by the Teuton ...

(now Kaliningrad) consist of numerous defensive walls, forts, bastions and other structures. They make up the First and the Second Defensive Belt, built in 1626—1634 and 1843—1859, respectively. The 15 metre-thick First Belt was erected due to Königsberg's vulnerability during the Polish–Swedish wars. The Second Belt was largely constructed on the place of the first one, which was in a bad condition. The new belt included twelve bastions, three ravelins, seven spoil banks and two fortresses, surrounded by a water

moat A moat is a deep, broad ditch dug around a castle, fortification, building, or town, historically to provide it with a preliminary line of defence. Moats can be dry or filled with water. In some places, moats evolved into more extensive water d ...

. Ten brick gates served as entrances and passages through defensive lines and were equipped with moveable bridges. The Königsberg fortifications became largely obsolete even before the completion of construction due to the rapid development of

artillery Artillery consists of ranged weapons that launch Ammunition, munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and l ...

. Following the military setbacks of

Nazi Germany Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German Reich, German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a Totalit ...

, however, they became strategically important again (particularly during the East Prussian offensive in 1945).

Major fortifications

Astronomic Bastion

The Astronomic Bastion (German: ''Bastion Sternwarte'') was erected in 1855-1860 and received its name from its proximity to the Königsberg Observatory. The bastion's wall was demolished in 1910. Subsequently the bastion was used to accommodate the Russian OMON for some time. Later the structure was bought by the Russian MP Asanbuba Niudyurbegov.

Bronsart Fort

The Bronsart Fort () was constructed in 1875-80 and is named after Prussian general Paul Bronsart von Schellendorff. It did not suffer much during military actions, remaining in quite good condition.

Dohna Tower

The Dohna Tower () was built in 1858 in Neo-Romanesque style and is named after Prussian politician Friedrich Ferdinand Alexander zu Dohna-Schlobitten. Following its restoration after World War II the tower started to accommodate the Amber Museum.

Friedrich Wilhelm I Fort

The King Friedrich Wilhelm I Fort, originally known as Quednau, is the largest fort of Königsberg.

Gneisenau Fort

The two-storeyed Gneisenau Fort was named after Prussian field marshal August von Gneisenau. It was heavily damaged by Soviet troops during World War II.

Grolman Bastion

The erection of Grolman Bastion, which was named after Prussian general Karl von Grolman, was finished in 1851. It is strengthened with

casemate A casemate is a fortified gun emplacement or armoured structure from which guns are fired, in a fortification, warship, or armoured fighting vehicle.Webster's New Collegiate Dictionary When referring to antiquity, the term "casemate wall" ...

s and

caponier A caponier is a type of defensive structure in a fortification. Fire from this point could cover the ditch beyond the curtain wall (fortification), curtain wall to deter any attempt to storm the wall. The word originates from the French ', meaning ...

s inside its wall and consists of lesser Oberteich and Kupferteich Bastions.

Pillau Citadel

The construction of stone Pillau Citadel started in the beginning of the 17th century. The citadel gained its final appearance by the beginning of the 18th century.

Stein Fort

The large Stein Fort was named after Prussian statesman Baron vom Stein. It remained in better condition than some other fortifications because it lay a bit aside from the places of the main Soviet attacks during World War II.

Minor structures

Barnekow Fort

The Barnekow Fort is one of the small forts, named after Prussian general Albert von Barnekow.