The church of Saint John the Baptist in Siewierz is one of the oldest in Poland. It may have been built before 1144. Its walls made of slabs, small size, The modest, small building devoid of decoration, whose walls are made of slabs, points to its Romanesque origins. According to the fifteenth - century chronicler, Jan Długosz, the founder of the church was Piotr Włostowic called Dunin, palatine of Prince Bolesław Wrymouth. He was a significant figure and the person was the subject of legends. The church of Saint John Baptist testifies to the great importance of Siewierz at the beginning of the Polish state.