In 145, Hardegg was first mentioned in a certificate from Elisabeth von Schleunz, and “Otto de Hardeck” is cited as a witness to the donation. But before that there was …
Relatively well-preserved castle ruins. Definitely worth a detour if you are hiking through the Kajatal from the Thaya up towards Merkersdorf. It is not always open though.
The Seefeld-Kadolz Castle was originally an old Kuenring seat with a moated castle. The castle was built in the short time of only 5 years (1710-1715).