Only discontinuous sections of the fortification wall and a hexagonal south-east bastion have been preserved from the original system of the town’s fortifications, which probably consisted only of a city wall with a water moat and cylindrical towers. The 180 - 200-cm-thick city wall was stoned with roughly coursed sandstone; the preserved sections, which reach the height of 7 m at some spots, can be found along the whole periphery of the historical centre. On the inner side of the wall there are traces of sparing of the beams of the defensive gallery. The building of the city walls can be assumed as early as the 1380s, at the turn of the 15th century at the latest. The entrance into the town had been protected by the Upper Gate and the Lower Gate, which were pulled down in 1842. The city walls were continuously renovated and modified. The south-east polygonal bastion dates back to 1613.