| Karlsborg Fortress | |
|---|---|
Karlsborgs fästning | |
| Karlsborg in Sweden | |
 Aerial photo of the Fortress (picture taken from the west). | |
  Karlsborg Fortress  Karlsborg Fortress  Karlsborg Fortress | |
| Coordinates | 58°31′55″N 14°31′50″E / 58.53194°N 14.53056°E |
| Type | Fortification |
| Site history | |
| Built | 1819–1909 |
| In use | Active as a fortress 1831–1925 Training Garrison 1925– |
| Materials | Limestone, gravel |
| Garrison information | |
| Past commanders | Oskar Sylvander (1904–1919) Christofer Lemchen (1911–1918) William Bergman (1919–1927) |
 | This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (January 2023) |
 | This article's lead section may be too long. (January 2023) |
Karlsborg Fortress (Swedish: Karlsborgs fästning) is situated on the Vanäs peninsula in Karlsborg by lake Vättern, the province of Västergötland, Sweden. Construction on the fortress began 1819 to realize the so-called central defense idea adopted by the Swedish military after the Finnish and Napoleonic Wars. The site was chosen by Baltzar von Platen in connection with the construction of the Göta Canal.
The intent of the central defense idea was that the King, the Council, the Riksdag and central command functions would, in the event of an attack against the kingdom, pull back and ensconce themselves in this fortress in the middle of the country. Even the gold reserves of the central bank of Sweden were to be safeguarded in the fortress in times of trouble. The fortress is one of northern Europe's largest buildings and consists primarily of limestone from Omberg.