u/ReplacementNo5581

I just zoomed out the map all the way just to see if i missed something exploring and saw these 2 areas off to the side. At first I assumed that it was just a stylistic choice but then quickly realized that no other part of the map that is not part of the playable area has this shading. This shading is specific to unexplored playable regions of the map. But I see no roads, tunnels, pathways, or even Floo flame symbols to get there? Is this just a glitch or some kind of mystery/easter egg situation?