Trelleborg - Viking Ring Fortresses - (Viking Castles)
Trelleborg
TRELLEBORGS, were viking ring fortresses, in Denmark, and Sweden. (Gatehouse) http://en.wikipedia.org/wiki/Viking_ring_castle | Викинги, Архитектура, Здания
Port of Trelleborg - Wikidata
File:Trelleborg Eingangsbereich der Wallanlage.jpg - Wikimedia Commons