Hardegg Castle was first mentioned in an 1145 deed, it was acquired by the Counts of Plain about 1187. Hardegg itself is first documented as a town in 1290. Located on the border with the Kingdom of Bohemia, the area was devastated during the Hussite Wars in 1425. In 1483 Hardegg was bequeathed to the Habsburg archdukes of Austria.
Emperor Maximilian I granted Hardegg to his ministeriales of the Prueschenk noble family and elevated them to immediate Counts of Hardegg in 1499. Two years later Count Ulrich purchased the Bohemian County of Kladsko from the Dukes of Münsterberg. From the Thirty Years' War onwards the castle decayed, until it was acquired by the Khevenhüller dynasty and rebuilt in the late 19th century according to plans designed by Carl Gangolf Kayser.
After World War II until the fall of the Iron Curtain, Hardegg was particularly isolated. The only connection to the Czech Republic is via a bridge built in 1874 across the Thaya to the neighbouring village of Čížov.
The Externsteine (Extern stones) is a distinctive sandstone rock formation located in the Teutoburg Forest, near the town of Horn-Bad Meinberg. The formation is a tor consisting of several tall, narrow columns of rock which rise abruptly from the surrounding wooded hills. Archaeological excavations have yielded some Upper Paleolithic stone tools dating to about 10,700 BC from 9,600 BC.
In a popular tradition going back to an idea proposed to Hermann Hamelmann in 1564, the Externsteine are identified as a sacred site of the pagan Saxons, and the location of the Irminsul (sacral pillar-like object in German paganism) idol reportedly destroyed by Charlemagne; there is however no archaeological evidence that would confirm the site's use during the relevant period.
The stones were used as the site of a hermitage in the Middle Ages, and by at least the high medieval period were the site of a Christian chapel. The Externsteine relief is a medieval depiction of the Descent from the Cross. It remains controversial whether the site was already used for Christian worship in the 8th to early 10th centuries.
The Externsteine gained prominence when Völkisch and nationalistic scholars took an interest in the late 19th and early 20th centuries. This interest peaked under the Nazi regime, when the Externsteine became a focus of nazi propaganda. Today, they remain a popular tourist destination and also continue to attract Neo-Pagans and Neo-Nazis.