As others have said, most major tourist attractions and department
stores will have at least reasonably good toilet facilities and all
restaurants are obliged to have toilets. Facilities at railroad
terminals are not always as good as one might hope!

I don't think you will find any of this a problem so long as you take
preventative action by passing a department store, restaurant or
tourist attraction (and there are an awful lot of all three!) at the
sort of frequency required by a 4-year-old!

As nobody else seems to have mentioned it, many of the toilets in
railway stations, other public attractions and even in department stores
nowadays, are pay on entry, so make sure you have plenty of small change
(20p usually) handy.
--
Spyke
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