OSM has been outstandingly good for finding public toilets almost wherever I went.
Basically this
Fiddle with the query, and you can extract pretty much whatever you want from the OSM database
Years ago, as a frustrated young parent, I created a similar project which helped me find toilets near me. I used OSM's Overpass Turbo API and it was an interesting experience.
This way I got a map that shows at a glance where the closest toilets are, as well as playgrounds, picnic tables, castles, ruins, water mills and lavoir/wash-houses (these are the areas that I've found to always be nice places when you have to stop on the way to rest and eat).
Surprisingly large number of places have them, but too large a fraction have nothing in the men’s room.
I remember the first time (before I had kids) I saw one in a men's toilet, and I was very impressed with how progressive it was. It was in the cafe toilets at St-Martin-in-the-fields church in London (the one on Trafalgar square). It has taken a long time, but we have come a long way since then (but much further to go, in terms of catering to, and valuing fatherhood).
These are basically impossible to find in the US, especially in big cities.
https://www.stadt-zuerich.ch/de/stadtleben/zusammenleben/oef...