The fortress in Bač is the most significant and the best-preserved medieval fortress in Vojvodina. It was erected around the mid-XIV century on a small island of the Mostonga River, which has since run dry today. Bač is a type of a “water city”, structured so as to defend the low-land marshy environment surrounding the city. On all sides, the city was surrounded by the river and approached by maneuverable bridges. The main tower in the courtyard is one of the most beautiful examples of late-medieval donjons in this part of Europe. The city was burnt and deserted at the beginning of XVIII century. Today, the fortress is open for visitors, and hosts European Heritage Days, exhibitions and folklore concerts.