High Quality Content by WIKIPEDIA articles! Jomsborg (German: Jomsburg) was a semi-legendary Viking stronghold at the southern coast of the Baltic Sea (medieval Wendland, modern Pomerania), that existed between the 960s and 1043. Its inhabitants are known as Jomsvikings. Jomsborg`s exact location has not yet been established, though it is maintained that Jomsborg was somewhere on the islands of the Oder estuary.Lauritz Weibull dismissed it as a legend.