Apart from when the central government has closed off the whole country to potentially crazed foreign sports maniacs who might be planning all kinds of anti-Olympic evil, the mainland has done a great job of opening up since the dark days of the 1960s and 70s.
Nowadays, with money and a smattering of Putonghua, there really is nothing you can't do; nowhere you can't go. Or so I thought.
Last summer, while on the way to Kazakhstan with friends E and K, we found ourselves in one of those "let's pick a town with an interesting name and go there" places in Xinjiang - He Jing, which translates as "peaceful and quiet".
"Sorry, but we can't accommodate foreign friends," said the hotel receptionist. That old chestnut. So we're "friends" but you won't accept our custom?
Fuming, we got in a taxi and drove from one hotel to another, with the same result. Waving my Hong Kong ID card saying, "I'm a Hong Kong compatriot" usually works in these No Foreigners hotels, but not this time.
Finally, we found a hotel run by Mongolians who took pity on us fellow ethnic minorities and let us stay, albeit with much sucking of teeth.
The little town was surrounded by spectacular scenery and we decided to head for a seemingly nearby mountain range. On and on we trudged across barren rocky desert-y nothing, the mountain range strangely receding from view with each step. Instead of being close, it was, in fact, miles away.
Just as we were about to turn around, we saw a tiny sign in Chinese that said, "Military area, no digging". No problem, we had nothing to dig with and were getting hungry anyway. Back on the road, we were intercepted by two Uygurs in a white car. In their rather shabby get-up, they looked like a tax collector and his obese uncle, but they identified themselves as the People's Police and said they would drive us back to the hotel. We got the impression that "no it's OK, we'll walk" was not an option.
How had they found us here in the wilderness, with not a person in sight? The kind farmer we had asked for directions must have dobbed us in.
Instead of eating great food and frolicking with locals, we had to spend the night under house arrest in the hotel "for our own safety". The place seemed dangerous all right: three children, several fruit stands and a farmer were all we had encountered.
But, in all fairness, how would they have known we weren't evil spies sent from some foreign enemy, hell-bent on taking down the country? We did have cameras, after all. And hats.