The Heldrungen moated castle is the only completely preserved fortified moated castle of French fortification architecture in Germany. The first castle was built here at the end of the 12th century. From 1512 to 1519, the complex was rebuilt into a Renaissance moated castle and the extensive ramparts with two moat systems were built. After the Peasants' War battle near Bad Frankenhausen in 1525, peasant leader Thomas Müntzer was imprisoned here. From the 18th century onwards, the fortress became less and less important. Extensive renovation and reconstruction work began in the 1970s.

Today, the castle is home to a youth hostel, so interested visitors can only explore the grounds with the moat.