It used to be enough to go to a spa for a salt scrub and a few yoga classes and maybe to squeeze out a couple pounds in a sweat lodge. But for the growing cadre of self-optimizing, data-­loving wellness-­seekers who think nothing of dropping a few grand to decode their DNA so they can stave off disease and decrepitude, pampering alone doesn’t cut it anymore.   Medical tourism is nothing new, of course, and renowned wellness spots at Baden-Baden itself was a nineteenth-­century mecca for European aristos and cultural elites (from Turgenev to Twain) seeking the curative boost of its mineral hot springs. Brenners, whose main building is a 102-year-old Belle Époque structure overlooking the flower-carpeted banks of the River Oos, also encompasses the recently renovated Villa Stéphanie residential spa annex, previously a rehabilitation clinic. Its new program offers referrals to seven on-site experts in fields including gynecology, ophthalmology, cardiology, physiotherapy, and aesthetic medicine. A medical-care consultant helps patients navigate appointments and can follow up with them—and their own doctors—once they’re home.   Learn about the top 20 wellness spots around the world at this Condé Nast Traveler article by Alex Postman.