The ruins of the imperial castle of Kyffhausen are located on the northeastern rim of the range on a hill, the Kyffhäuserburgberg (), an approximately 800 m (2,600 ft) long eastern spur. The castle is in the parish of Steinthaleben, about 3 km (1.9 mi) northeast of the village of Rathsfeld, in the Thuringian municipality of Kyffhäuserland, near the town of Bad Frankenhausen in Kyffhäuserkreis. The Goldene Aue ("Golden Water Meadows", ca. ) plain to the north, including the villages of Sittendorf and Tilleda roughly 280 metres below, are parts of the municipality of Kelbra in the Mansfeld-Südharz district of Saxony-Anhalt.
The castle grounds are part of the Kyffhäuser Nature Park – situated about 300 m (980 ft) south of its northern boundary.
Archaeological findings of several shoe-last celts at the summit denote a settlement already in the Neolithic period. Excavated Bronze Age ceramics may stem from devastated tumuli erected on the prominent spur. In the 1930s, remnants of fortress dating from the Hallstatt era were discovered.
A first castle high above the Tilleda Kaiserpfalz was probably erected under the rule of the Salian emperor Henry IV, in order to protect his royal domains south of the Harz mountains. Nevertheless, it was not mentioned until 1118, when it was demolished by the Saxon duke Lothair of Supplinburg after his forces had defeated Emperor Henry V at the 1115 Battle of Welfesholz.
Reconstruction started shortly afterwards and was accomplished under the rule of the Hohenstaufen emperor Frederick Barbarossa, who stayed downhill at Tilleda several times. The rebuilt castle complex of bright red sandstone then spread over large parts of the Kyffhäuserberg ridge; administrated by Hohenstaufen ministeriales, it was meant as an expression of imperial power in the region.