Nienburg is a town in the district of Salzlandkreis in Saxony-Anhalt, Germany. It is located in the lower Saale valley, approx. 5 km northeast of Bernburg. In June 2005 its population was 4,449.
Nienburg is first mentioned in travel records dating from 961. The medieval centre of the town is occupied by the Benedictine monastery, Nienburg Abbey, later turned into a castle, recently destroyed by fire. The church of the monastery, over 1000 years old, was inaugurated in 1004, and is beautifully preserved to this day.
In 1623, during the Thirty Years' War, part of the town was destroyed. On December 6, 1825, an early cable-stayed bridge over the river Saale collapsed during a celebration honoring the bridge's patron. 55 people were killed, 60 were injured, and two people remained missing. The bridge had been open for just three months. A contributing factor may have been youths attempting to get the bridge to sway to the tune of "God Save the King."