Phongsali, the northernmost province of Laos bordering Pu'er and Xishuangbanna in Yunnan Province, China, is home to a lot of mountain tribes. Weather there is cool. You can find a local guide to visit nearby mountain tribes in the capital Phongsali on foot (car-free). It takes at least 2 days. The Manzhuang (China)/Paka (Laos) port is very close to Phongsali, and it takes 1 day to reach it from Udomxai.