High season in the French Riviera may be the summer months, but the region originally gained its popularity in the late 18th century as a winter retreat for royals and wealthy British aristocrats. Doctors prescribed the Mediterranean climate’s natural healing powers, and everyone from Queen Victoria to Robert Louis Stevenson flocked to the Riviera each winter to be cured. The visitors even earned a nickname: les hivernants, the winterers. “Nice has always been a year-round destination, known particularly for its winter sun, attracting many Northern Europeans who come to escape harsh winters,” says hotelier Valéry Grégo, the visionary behind Hôtel du Couvent in Nice’s Old Town, which opened in early summer following a decade-long, $100 million transformation of a 17th-century convent. As someone who first moved to Nice in the fall months and has spent many winters in the South of France, I understand the appeal—and so do the handful of new, year-round hotels launching wellness-focused programs. Lily..