Altes Schloss, Castle ruins in Dillingen/Saar, Germany

Altes Schloss is a castle in Dillingen/Saar whose origins lie in a medieval moated castle, probably built around 1340 under Arnold II of Siersberg and first documented in 1357. A side arm of the Prims still flows around the site. Wilhelm Marzloff von Braubach had large parts of the castle demolished to build a Renaissance palace, and parts of that building survive in the present structure.

Altes Schloss is a water castle, probably built around 1340 under Arnold II of Siersberg and first documented in 1357, when his son Eberhard pledged half of the Dillingen estate to Count Henry of Veldenz for 400 guilders. In 1591 Wilhelm Marzloff von Braubach had large parts of the medieval castle demolished and replaced by a Renaissance palace, whose fabric survives in the present building. French troops occupied it in 1674, and imperial and Lorraine troops under Count Starhemberg plundered it on 15 May 1677.

The castle's name, Altes Schloss, distinguishes it from Dillingen's later castle; the Dillinger Hütte owns it and leases it to the town, which uses it for cultural events. Since 1983 a Förderverein has supported its restoration. A side arm of the Prims still flows around the building, a reminder of its origin as a Wasserburg.

The ruins are open to visitors throughout the year, and forest paths around the site lead to different viewpoints. Wearing sturdy footwear is advisable since the ground is uneven and paths can be slippery.

The castle is a Wasserburg, a water castle in a valley, not a hilltop fort: a side arm of the Prims still flows around it today. Its position near the mouth of the Prims and Nied into the Saar let its owners control traffic on the rivers.