A very long time ago (I'm going to hazard a guess around ten years ago?) there was a thing called World Park Project that someone had created. It was a Google
Earth overlay with all of the operating parks in the world. You could toggle them on/off individually, and then use Google Earth to show them all on the map/globe.
A cursory Google search now suggests this project might be dead though (or rather, I don't see any references to it).
I've been keeping the latitude/longitude coordinates (I grab them from RCDB's Map links) for all the parks I've visited for many years now, and use
https://mapmakerapp.com/ to plot them all. I generally just update the map at the end of each year though. There is a way to do it automatically in Excel, but it's linked to Bing Maps and I've never quite got it to work properly.
Low-res copy of my global park map.