The remains of the Castle can be visited
Front Wartenberg Castle (Ruin)

On a rocky spur near Muttenz in the canton of Basel-Landschaft, Switzerland, lie the ruins of Vorderer Wartenberg. It is part of an ensemble of three medieval castles on the Wartenberg.
History+
The origins of the complex date back to the late Carolingian period, with the visible fortress remains constructed in the mid-12th century and expanded over the following century. Until the end of the 13th century, the three Wartenberg castles formed a single unit. The Chapter of Strasbourg appears as the first traceable owner, who likely enfeoffed the castles to the Counts of Homberg in the 11th century. Later, the Frohburgers, also known as Neu-Hombergers, and their liegemen, the Marschalk von Wartenberg, inhabited the complex.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 47.5214, 7.6578