When an offer came up to visit Hong Kong to teach a two-weekend course in the psychology of consumers and consumption ("Consumer Behavior"), I said "Yes".
This affirms one of the key principles of "manipulating" consumer behavior: just give customers want they want. It's a lot easier than trying to push them towards that which they don't want.
The course was then cancelled, but they agreed to pay for my non-refundable airline tickets, and so I went anyway.
Hong Kong is of course a major city (population 7m), and nearby mainland China features a set of massive megatropolises including Guangzhou (population 13m) and Shenzhen (population 11m).
Despite that, Hong Kong features some fascinating wilderness spots. Here's the ones I explored and highly recommend.