Something that I've been low-key looking for is a way to create my own continent/world map and then be able to zoom into specific regions and add details, and then be able to zoom/click on a specific town/dungeon/encounter site and see the gridded map with terrain features and the ability to put notes off to one side. This seems to me like an integration of a highly zoomable world creation app and a dungeon creator app and a city builder app. I've only ever found a world creator app that I like. 

General thoughts from the community?

Also, the reason this is here and not reddit is because I think that D&D Beyond should include some sort of basic map tools, at least for the standard Far Realms and possibly purchasable adventures. 

I believe hexographer has ways to link maps and child maps.

You can use google maps for this.

its a bit more work, but... it. is. AWESOME. if you get it done.

https://developers.google.com/maps/documentation/javascript/maptypes#ImageMapTypes

example: 
http://tamrielfoundry.com/map/

Realm Works lets you do this and much more. Here's what I have been doing with the Forgotten Realms.