The remains of the castle can be visited
Delmenhorst Castle

The moated castle of Delmenhorst was strategically located on the “Burginsel” (Castle Island) in the city of Delmenhorst, Lower Saxony. For almost five centuries, this complex formed the center of urban life and was a stronghold for the Counts of Oldenburg.
History+
Following the Stedinger Wars in 1234, the Counts of Oldenburg began constructing a moated castle in the marshy Delme lowlands. This complex, originally a small farm called “De Horst,” was surrounded by two moats and served to secure the conquered Stedinger territory. The first documented mention occurred on July 27, 1259, when Count Johann I of Oldenburg referred to the castle as “in castro nostro Delmenhorst” during a land sale. From 1281 to 1436, the lordship of Delmenhorst belonged to the elder line of the Counts of Delmenhorst before reverting to the County of Oldenburg. Between 1440 and 1482, Count Gerd the Brave ruled Delmenhorst, after which the territory fell to Münster. In 1547, Count Anton I of Oldenburg succeeded in reconquering the lordship and county. In the 16th century, the castle was expanded into a Renaissance palace with a pleasure garden. In 1667, the counties of Oldenburg and Delmenhorst became Danish. In the 17th century, the palace began to decay. From 1711, after the county was pledged to the Electorate of Brunswick-Lüneburg, the palace was sold for demolition.
Image: http://www.wehrbauten.de/thread.php?threadid=963
Location: 53.0456, 8.6271