This page is built with WordPress, using the Hello Theme as the base.
I looked for a while to find a map function that didn’t rely on the Google Maps API. I ended up using the most excellent plugin Travelers’ Map, which works great and with some creative use of tags and categories, allowed me to create a map functionality for the site that I had long wanted to do.
The Plugin uses open source map tiles and other data from OpenStreetMap & CARTO