There were two Schauenburg castles near Frenkendorf, Alt (or Old)-Schauenburg about southwest of the village on the top of Chleiflüeli hill and Neu (or New)-Schauenburg to the west. Alt-Schauenburg was probably built around 1275 as the seat of a junior branch of the Schauenburg family. The castle was occupied for less than a century. The 1356 Basel earthquake destroyed much of the castle and shortly thereafter the ruins were abandoned. The ruins were gradually buried, until 1949-50 when they were excavated and repaired. In 1976-77 additional construction helped preserve the site.