Altenburg Hillfort (Niedenstein)

The Altenburg is a prehistoric hilltop settlement near Niedenstein in the southern part of the Habichtswald Nature Park. The complex, which was surrounded by ring walls, is located on a wooded mountain, more precisely on a basalt plateau, the "Green Plate," at an altitude of about 450 meters. Hardly anything can be seen of the settlement today, its ring walls are partially destroyed or have fallen victim to weathering.
Source:
naturpark-habichtswald.de/media/attractions/altenburg-niedenstein#/article/2a7fd028-1b2f-44ec-8bd6-e6c722f9141e

Here z. B. Europe's only surviving door from the Iron Age was discovered in 101 BC.

"The Altenburg, also called green plate, is a prehistoric castle on the mountain near Niedenstein Altenburg in the Habichtswald Nature Park in Schwalm-Eder-Kreis, North Hesse (Germany).During excavations, which took place between 1905 and 1913, the castle complex was extensively studied and scientifically evaluated. Exposed were the ramparts, main wall, gates, culverts, and clay camps. The stone walls were originally reinforced by wooden structures. The total length of the ramparts was about 3000 meters; the core area of ​​the fortified hill colony was 15 hectares, the total area about 70 hectares. Several round pits were found to be wood-pitted pits and cisterns. A pit was used as a mash of a pottery.The finds are kept in the Hessian State Museum in Kassel and described in the Bürgerhaus Niedenstein, where a model of the historic facility is also located. On the basis of plates, which were attached in a refuge on the Altenburg, one can inform oneself about the history and the excavations of the Altenburg. "- de.wikipedia.org/wiki/Altenburg_(Niedenstein)