I have a Candian passport and will be doing a connection flight in Xiamen

I"m reading "Passengers transiting in Beijing, Chongqing, Harbin, Guilin, Kunming, Wuhan, Xiamen, or Tianjin cannot leave the administrative area of the transit city."

What they mean I can't leave the "adminstrative area of the transit city"? so I cannot leave the airport?? just wantt to make sure if i can do the 72 VISA free stay.
Thanks!