Shenzhen City Centre, China

With a population of 17.5 million, Shenzhen is the third-largest city in China and a bustling technology and financial hub. However, the bureaucracy can be a persistent headache, as evidenced by the strict hukou (household registration) system that limits access to public services. And while the subtropical climate brings mild winters, the summer months are hot, humid, and prone to torrential rain. Still, Shenzhen's breakneck pace of development and status as a global tech center make it an alluring destination for ambitious professionals seeking opportunity.