The area around Sangerhausen is rich in historical evidence of the Middle Ages. In the 10th century there were important crown estates in the southern Harz. There were palatinates in Wallhausen, Allstedt and Tilleda, and royal farms in Rottleberode, Berga, Breitungen and Lengefeld. The 5.6-hectare site of the Tilleda palatinate was excavated and developed as an open-air museum. Stone buildings were intended for the king and his entourage. They were protected by ramparts and ditches. The craftsmen lived in simple pithouses in the fortress-like part of the palace. Protection was provided by a stone enclosure wall, along which the houses of the guards also stood.
The excavation of the medieval village of Hohenrode near Grillenberg provides an insight into the rural way of life and economy in the Middle Ages. Stone foundations of buildings from the 12th - 14th centuries have survived to the present day and can be visited in the forest. In the exhibition of the Spengler Museum, models of Tilleda and Hohenrode as well as original medieval finds can be seen.