The Heidenmauer ('heathen wall') is a circular rampart or ringwork, two and a half kilometres long, which was built by the Celts around 500 BC. The wooden elements of the wall have disappeared over the course of time by rotting away, but the stones have survived. Copious numbers of pottery finds have enabled a very precise dating. Almost all the containers are hand-made, only a few show traces of having been turned; this technology first appeared after ch 500 BC. in the La Tène period. Other finds included iron, long knives as well as querns, pyramidal stones that were stuck point-down in the ground in order to provide the base for the milling of corn. In addition there is also evidence of milk production and iron smelting.
In the 4th century A. D. a small part of the circular rampart as well as the Kriemhildenstuhl below was used by the Romans as a quarry.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.