Ring fortress, Eketorp, Öland (S) | Castle, Castle art, Historical architecture
Viking-Age Aggersborg - Medieval Histories
Denmark, viking ring castle, at the Trelleborg Museum. Trelleborg (Slagelse). The Trelleborg (or Trælleborg) west of Slagelse on the Danish island of Stock Photo - Alamy
Trelleborgen - Viking fortress in Trelleborg | GuidebookSweden
Viking ring fortress wall, artwork Photograph by Science Photo Library