The south tower, also known as the parish tower, is the point of entry to the castle from the town, to which it is connected by stairs. This single-storey rectangular building was built in the second half of the 14th century and served as the parish office until the 15th century. A covered staircase was added after 1780 and the first floor was modified to allow access. Bells were installed on the first floor at the end of the 19th century.
The south tower is now the public entrance to the castle and the ticket office is installed here.