The fairy-tale Château de Joux [Chemin du Frambourg au Fort du Larmont, +33 381694795 ad/ch €6/3.20] is the guardian of the France-Switzerland trade route. Ascending on the Jura Mountains, the castle spans over 2 acres and used to function as a military stronghold (thanks to its natural fortifications in the form of mountain ranges). The castle is almost millennia old and has functioned as a feudal home, a military fort and currently as a tourist attraction. Today, it is home to the Musée d’arms and features many ancient architectural properties as well. Guided tours are recommended (for English tours book in advance).