Älvsborg fortress

Älvsborg, also Elfsborg Fortress, is a large sea fortress in Rivö fjord, within modern Gothenburg, Sweden. Situated at the mouth of the Göta River, it served to protect medieval Sweden's only access to the North Sea and Atlantic Ocean and the nearby settlement of today's Gothenburg and its four predecessors (Lödöse, Nya Lödöse, Älvsborg and Charles IX's Gothenburg).

The original Old Älvsborg Fortress (Älvsborgs fästning or Älvsborgs slott) was located on the mainland, on the southern shore of the estuary, above modern Klippan. Only few ruins are visible today in the vicinity of the Carnegie-pier.

The old fortress was dismantled and relocated to one of the islands in the estuary, in the 17th century. This New Älvsborg Fortress (Nya Elfsborg) is still maintained.

In 1643, a settlement in New Sweden, North America, was named Fort Nya Elfsborg ("Fort New Älvsborg"), after the Swedish fortress. This settlement was abandoned in 1655. Gothenburg was the main centre for Swedes emigrating to America, and the fortress would have been one of the last sights the emigrants saw on leaving the country.

Old Älvsborg Fortress
A fortified outpost was especially important for Sweden when the area north of Älvsborg, Bohuslän, was part of Norway (until 1658), and the area south of it, Halland, was part of Denmark (until 1645). Sweden's only Atlantic settlement, Gothenburg's first predecessor Lödöse ("Gothenburg 1") at the mouth of the Göta Älv, was built about 1200, superseded by New Lödöse ("Gothenburg 2") near the modern town.

In 1473, New Lödöse was granted substantial privileges. The Old Älvsborg Fortress was built in the 14th century, located at the Klippan area near what is now the harbour entrance of Gothenburg. After the Danes several times easily conquered the fortress, the fortification works was gradually expanded. New Lödöse was burned down by Danish forces in 1521, and after it was initially rebuilt at the same spot in 1526, it was later relocated ("Gothenburg 3") near the Älvsborg fortress, west of the modern town.

In 1563, when the Northern Seven Years' War broke out, the Swedish burned down this town by themselves to not let Denmark capture it, and Denmark took over Älvsborg Fortress. The war ended with the Treaty of Stettin (1570), which obliged Sweden to pay 150,000 riksdaler for the ransom of the fortress of Älvsborg. To pay this extraordinarily high amount of money, Sweden heavily taxed all moveables in the country, resulting in further impoverishment of the war-torn population. Unburned towns had to pay one twelfth, peasants one tenth, burned down towns one eighteenth of their properties' value. In 1603, the adjacent town was again relocated ("Gothenburg 4") to the site of the channel opposing Älvsborg Fortress, it was the first town called "Göteborg", built by Charles IX of Sweden. The town was annilihated by Denmark in 1611, who took possession of Älvsborg between 1612 and 1619.

Today, only few remains of the fortress are preserved, located at 57.68972°N, 11.90722°W.

New Älvsborg Fortress
New Älvsborg Fortress was built in the 17th century near the ruins of the old fortress, but on a small island where the Göta Älv river meets the sea. It protected the new town of Gothenburg, founded in 1621 by Gustavus Adolphus of Sweden. New Älvsborg Fortress today is a listed building (byggnadsminne) and a popular tourist attraction.