Badenweiler is a health resort and spa in the Breisgau-Hochschwarzwald district of Baden-Württemberg, Germany, historically in the Markgräflerland. It is 28 kilometers by road and rail from Basel, 10 kilometers from the French border, and 20 kilometers from Mulhouse. The nearest big city on the German side of the border is Freiburg, about 30 kilometers away. Badenweiler lies at the western edge of the Black Forest. It is sheltered by the Blauen, 1,164 m, and the climate is excellent. Its parish church was built at the foot of an 11th-century castle which belonged to the margraves of Baden and was destroyed by the French during the wars of Louis XV.
Many visitors come to Badenweiler for the warm mineral springs, with temperatures of 21 °C, others for its whey cure, and still others on account of its equable climate and picturesque surroundings. There is a Kurhaus and a park of 15 acres containing a historic arboretum, as well as a grand-ducal castle. In 1784, the well-preserved Roman baths were discovered there.