Old Älvsborg - Credit: Wikimedia Commons
Älvsborg (literally "river stronghold" in Swedish), now generally known as Old Älvsborg () or Älvsborg Castle () to distinguish it from the later New Älvsborg and Älvsborg Fortress, was a medieval castle situated on the rocky outcrop known as Klippan, on the south bank of the Göta Älv river within the urban area of the modern city of Gothenburg. Read more on Wikipedia
Source: en.wikipedia.org