FRAUENBURG, a town of Prussia, province of East Prussia, government district of Königsberg, is situated on the Frische Haff, and at the mouth of the Baude, 41 miles S.W. of Königsberg. It is the seat of the Roman Catholic bishop of Ermeland. The cathedral, which stands on an eminence, possesses six towers, and forms a kind of fortress. The astronomer Copernicus was canon at Frauenburg, and there is a monument to him in the cathedral. He is said to have constructed the tower containing machinery for supplying the town and neighbourhood with water. The tower is no longer used for this purpose. The population of Frauenburg is about 2500.