Alt-Schauenburg is a ruined castle in the commune of Frenkendorf. It is located near the border of France and Germany, and little of the castle remains because of geological events.
There were two Schauenburg castles near Frenkendorf, Alt-Schauenburg about 1 km southwest of the village on the top of Chleiflüeli hill and Neu-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.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.