Trelleborg near Skåne
Trelleborg is a ring fortress near Skåne. The fortress was built during the reign of Harald Bluetooth.
Trelleborg dates back ca. 980, when Harald Bluetooth ruled Denmark. Skåne was part of Denmark back then, which explains the location of the fortress.
Trelleborg was constructed the same way as Harald Bluetooth's other ring fortresses; Aggersborg by the Limfjord, Fyrkat near Hobro, Nonnebakken near Odense and Trelleborg near Slagelse.
Trelleborg lies near the Swedish city of Trelleborg. It is believed that the city was named after the viking fortress. These days, no traces remain of the fortress, neither do any traces remain of the fortress Nonnebakken.