The Barenburg with 5.5 ha of interior space is a large walled castle near Eldagsen in Lower Saxony. It lies on a steeply sloping mountain spur of the Osterwald about 350 above N.N. Their time of origin is presumed in the pre-Roman Iron Age, an archaeological excavation has not yet taken place. The function of the plant as a refuge for the population should have lasted until the Middle Ages, as it belonged to the possession of the nearby monastery Wülfinghausen.Source Wikipedia