I prefer to translate "Bad" as a "health/spa/wellness resort town" or "mineral springs resort (town)" if it does indeed have them. Not to be confused with a "resort spa" or, for that matter, which I did happen to see at times - even "spa" (that would be this, a bit dated today, 19th/early 20th-century meaning). I tend to think of a "spa" today as it is I guess usually understood - as a single, often somewhat smaller establishment (unless the context indicates some hotel with health, beauty or wellness offering, or even sometimes "a spa in a resort." For the interested, check out this article:
https://www.tripsavvy.com/what-is-a-spa-3085921Curious if you agree.