It is based on mapy.cz [1] - Outdoor layer. It is mostly OSM based (plus lot of their own data for Czechia and Slovakia). Mapy.cz belongs to same guy, who runs

It is based on mapy.cz [1] - Outdoor layer. It is mostly OSM based (plus lot of their own data for Czechia and Slovakia). Mapy.cz belongs to same guy, who runs Windy (Ivo Lukačovič [2]). IMHO it is best readable map on the internet and when I am used to it, I cant find anything on Google Maps. [1] https://en.mapy.cz https://en.mapy.cz [2] https://en.wikipedia.org/wiki/Ivo_Luka%C4%8Dovi%C4%8D https://en.wikipedia.org/wiki/Ivo_Luka%C4%8Dovi%C4%8D