Having just gone through Belgium and the Netherlands, it’s a huge relief to know that public restrooms are definitely around if you’re willing to part with some change.
The card readers are all over the UK's largest parks, too.
(A nasty issue I encountered in Iceland was that my debit card did not support Icelandic vendors, and as a result, could not be used to purchase anything which the strip reader. I jumped many turnstiles, sorry Iceland...)