Wisłoujście Fortress built
1482 CE.
Shown on the map at 54.396°, 18.679°.
Wisłoujście Fortress (Polish: Twierdza Wisłoujście, German: Festung Weichselmünde) is a historic fortress located in Gdańsk by the Martwa Wisła river, by an old estuary of the river Vistula, flowing into the Bay of Gdańsk. The fortress is located close to the Wisłoujście borough, Westerplatte and the Port Północny (Northern Port). It is listed as a Historic Monument of Poland.
Text from the Wikipedia article Wisłoujście Fortress, licensed CC BY-SA 4.0.