I'm also after something like this; with an uploaded map, adding points of interest, which gives me more detail about it.

But what I'm also after, if possible, is the ability to add selectable regions (likely with the use of an overlay), with the ability to use different levels (like state levels and province levels), and I can get the details depending on which overlay I'm using.

This last one would be a fantastic bonus, but if I could somehow tie it to a fantasy date system, so I can see the territory changes over a period of time, similar to what EU4 (and also this really cool world map project online that covers historical territory) does.

I'm likely asking too much, but I'm hoping there is something like this that can give me so much control over my maps and just allows me to easily reference material more than any handwritten stuff could ever provide, even if it's just the first two.