If all the different kinds of snack food from all the different parts of China were put together under one roof, I think the country would finally have a monument that is genuinely visible from space.

But since this has not yet happened, you will need to retrain your tastebuds every time you arrive in a new city, since tastes vary and so do locally available ingredients. For example, in coastal Dalian you can buy little conical seashells, and I watched in fascination the first time I saw these being eaten by a woman on a bus. She would take a shell and break off the tip, then into the other end insert an ingenious homemade device (a bent pin) and extract the tiny animal from inside. Afterwards, she would toss the shell out the window of the bus.

Some snacks are seasonal. Of course this is especially true of fresh fruit, which is a very popular snack in China and not too expensive if you buy it in high season. Delicious baked yams are available during the colder months, presumably because they don’t sell well in the summer. You eat the pale yellow flesh inside, not the thick skin. In bitterly cold Heilongjiang Province, they have an interesting way of preserving pears and persimmons during the winter: they leave them outside to freeze. You can take these home, let them thaw partially, and eat them. Walnut season began not long ago, and Western China seems to be the place for walnuts.

It’s also the sound of a sunflower seed cracking between your teeth that a lot of people like, although this can become quite noisy when you have, for example, a whole cinema full of people eating sunflower seeds while they watch a movie.