Passport? Good.

Compared across countries

Are public toilets free?

For a trip that crosses borders — the same question, answered country by country.

The pattern

Free in all four, and stations are the reliable place to look. The paper is what differs: China says bring your own, Taiwan says flush it, and the bin beside the bowl does not mean the same thing in each.

Sort the practical stuff before you fly.

eSIMs, rail passes, and airport transfers — the things worth booking before you land.