The Gniew Castle was the most powerful claim of the Teutonic Order on the left bank of the Vistula. Built at the turn of the 13th and 14th centuries, it was the home of the Knights commanders, and in the times of Poland, when the town belonged to Poland, it was a mayor"s seat. The castle was rebuilt in several times (granary, prison) and eventually burned in the Great Fire in 1921. Wikipedia