The Caracalla Therme is the modern thermal-bath complex next door to the Friedrichsbad, opened in 1985 and named for the Roman emperor who supposedly bathed at Baden-Baden during a campaign on the Rhine. It is far less ceremonial than its older neighbour — swimsuit required throughout the main pools, families welcome, day passes by the hour.
There are indoor and outdoor heated pools fed from the same hot springs as the Friedrichsbad, with whirlpools, jets, and a current channel. A separate upstairs sauna section is clothing-free in the German tradition. Good for an evening visit when you are tired from walking; less of a ritual experience than the Friedrichsbad, but easier to drop in.