🇸🇪 Sweden · Fortress
Bulverket
Medieval Gotland 12th c (1132) early Christian–Gotlandic Ting · Medieval Gotlandic chieftains (Gutar Christian early)
Bulverket — unique Scandinavian lake pile fortress (c.1132 CE dendro-dated, Medieval 12th c) on Tingstäde Träsk lake, central Gotland, 18 km northeast Visby.