Huizhou, China

The population of Huizhou, China is a hefty 2.9 million, but don't let that fool you - this city is no walk in the park for foreigners. The Hui Chinese dialect spoken here is so internally varied that even locals in different townships struggle to understand each other, let alone newcomers. And while the region's unique linguistic heritage is fascinating, the bureaucracy is a persistent headache, with identity-based dialect communities adding an extra layer of complexity.

For those with a high tolerance for paperwork and linguistic puzzles, Huizhou could be an intriguing destination. But for the average expat seeking a smooth transition, this city may prove more frustrating than fun.