Hazy Skies in a Growing City

Chiang Mai, the largest city in northern Thailand, is famed for having hundreds of Buddhist temples, some of which date to the city’s founding in the 13th century. This rich history—and easy access to hiking, waterfalls, and hot springs in the surrounding highlands, as well as being the setting of a hit movie in 2012—has turned the city into a hub of tourism that hosts as many as 10 million visitors per year.