Chiang Mai is the largest city in northern Thailand, the capital of Chiang Mai province and the second largest city in Thailand. It is 700 km nort…Chiang Mai is the largest city in northern Thailand, the capital of Chiang Mai province and the second largest city in Thailand. It is 700 km north of Bangkok in a mountainous region called the Thai highlands and has a population of 1.2 million people as of 2022, which is more than 66 percent of the total population of Chiang Mai province.