The

fortifications A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ...

of the former East Prussian capital

Königsberg Königsberg (, ) was the historic Prussian city that is now Kaliningrad, Russia. Königsberg was founded in 1255 on the site of the ancient Old Prussian settlement ''Twangste'' by the Teutonic Knights during the Northern Crusades, and was name ...

(now

Kaliningrad Kaliningrad ( ; rus, Калининград, p=kəlʲɪnʲɪnˈɡrat, links=y), until 1946 known as Königsberg (; rus, Кёнигсберг, Kyonigsberg, ˈkʲɵnʲɪɡzbɛrk; rus, Короле́вец, Korolevets), is the largest city and ...

) consist of numerous

defensive walls A defensive wall is a fortification usually used to protect a city, town or other settlement from potential aggressors. The walls can range from simple palisades or earthworks to extensive military fortifications with towers, bastions and gates ...

, 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 Polish–Swedish Wars were a series of wars between the Polish–Lithuanian Commonwealth and Sweden. Broadly construed, the term refers to a series of wars between 1563 and 1721. More narrowly, it refers to particular wars between 1600 and ...

. 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. Ten brick gates served as entrances and passages through defensive lines and were equipped with

moveable bridge A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. In American English, the term is synonymous with , and the latter is the common term, but drawbridge can be limited to the narrower, historical d ...

s. The Königsberg fortifications became largely obsolete even before the completion of construction due to the rapid development of

artillery Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during siege ...

. Following the military setbacks of

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

, however, they became strategically important again (particularly during the East Prussian Offensive).

Major fortifications

Astronomic Bastion

The Astronomic Bastion was erected in 1855-1860 and got its name because of proximity to the Königsberg Observatory. The bastion's wall was demolished in 1910. Subsequently the bastion was used to accommodate the Russian

OMON OMON (russian: ОМОН – Отряд Мобильный Особого Назначения , translit = Otryad Mobil'nyy Osobogo Naznacheniya , translation = Special Purpose Mobile Unit, , previously ru , Отряд Милиции Осо� ...

for some time. Later the structure was bought by the Russian MP Asanbuba Niudyurbegov.

Bronsart Fort

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

Dohna Tower

The Dohna Tower (german: Dohnaturm) was built in 1858 in

Neo-Romanesque Romanesque Revival (or Neo-Romanesque) is a style of building employed beginning in the mid-19th century inspired by the 11th- and 12th-century Romanesque architecture. Unlike the historic Romanesque style, Romanesque Revival buildings tended to ...

style and is named after

Friedrich Ferdinand Alexander zu Dohna-Schlobitten Friedrich Ferdinand Alexander zu Dohna-Schlobitten (29 March 1771 – 31 March 1831) was a Prussian politician. Biography Dohna-Schlobitten was born at Finckenstein (today Kamieniec, Poland) to Friedrich Alexander Burggraf und Graf zu Dohna-Schl ...

. 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

August von Gneisenau August Wilhelm Antonius Graf Neidhardt von Gneisenau (27 October 176023 August 1831) was a Prussian field marshal. He was a prominent figure in the reform of the Prussian military and the War of Liberation. Early life Gneisenau was born at Schil ...

. It was heavily damaged by Soviet troops during World War II.

Grolman Bastion

The erection of Grolman Bastion, which was named after General Karl Wilhelm von Grolman, was finished in 1851. It is strengthened with casemates 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 to deter any attempt to storm the wall. The word originates from the French ', meaning "chicken coop" (a ''capon'' ...

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 Henrich von 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.