. . . in the Black Forest, or anywhere within 200 miles of there, you should make every effort to visit Baden-Baden and take the waters. Baden-Baden is in the middle of a grouping of natural mineral springs, and many of the hotels have spas. There are also two municipal facilities, available for use by anyone staying in the town or day-trippers. The Caracalla is a modern facility, with pools, steambaths, fitness and even a "children's paradise."
But, if you want a true sybaritic experience, you must spend three hours in the Friedrihsbad, or Roman-Irish Baths. There, amidst exciting architectural visions, you can wash your dirt and cares away.
Let me be clear. If you have the typical North-American prudishness regarding nudity, you will not be comfortable here; except on Mondays and Thursdays, when the sexes bathe separately, you will be in the presence of naked people of the opposite sex. But if you are willing to dip a toe into the typical European sensibilities of modesty ("Nudity? Who cares?") you will have a wonderful time, and wind up feeling cleaner then you ever have been in your life. Do *not* be concerned that you might not be a supermodel. Few of us are (unlike the models in the pictures,) and *none* of the people you will see in the facility will care. It's a simple equation - go, forget you're naked, have fun.
When you get to Baden-Baden, your hotel staff will be happy to give you directions to the baths. Or, if you are a day-tripper and you're in the middle of the town, anyone will be happy to point the way. The town is easily walkable, and the baths are only a few hundred yards from anywhere.