The Sorbenturm is part of the old Ilburg. This was first mentioned in documents in 961, which is now considered the year Eilenburg was founded. The Sorbenturm is the only solid building in the Ilburg that has been preserved. It was probably built in the 12th century at the highest point of the approximately 220 by 150 meter plateau and served as a lookout and place of retreat. After two more castle keeps were built, probably in the 13th century, the Sorbenturm lost its strategic importance and fell into disrepair. In the middle of the 19th century it was therefore due to be demolished. But committed citizens saved and preserved this striking building in Eilenburg. The tower, which is now 16 meters high, has served as an observation tower since 1863. It was reconstructed in 1997/98.