Any cool hidden places in Shanghai??

Hi all! I am traveling to Shanghai at the end of this month for a week. I've heard so many interesting things about the city and very excited to explore. I've done my research on all touristy places I need to check out. But I am more interested in cool places not well known to tourists. These are hard to find on the internet. Especially when I don't speak the language. I would very much appreciate it if you could suggest your favorite place or part of the city. I will repay the favor if anyone is visiting Seoul, Korea. Thanks! :)

JuJu