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
1356 Basel earthquake
1356 Basel earthquake
Alt-Schauenburg Castle