Fort, prison, museum... The castle has had an unusual life, somehow befitting its exceptional position overlooking the impressive Cluse de Joux. This formidable eyrie has been watching over a narrow pass, erstwhile highly strategic, since the 11C. Today the castle still stands proud, having withstood the test of time and survived for more than ten centuries as guardian of the pass, all the while adapting to the changes in its architecture and its duties. Visit the dungeons and the Museum of Ancient Arms.