Comment by ThomPete

I wonder why we don't see more map apps like this.

Just of the top of my head:

Around the world route maps (people submit the trips they did)

Greatest explorers route maps (although I guess there might be some problems with historical accuracy)

Geek Spots Around the world

Known Military Bases around the world (and perhaps a strategy game on top)

The use of large scale maps are IMHO still a very underutilized area because most go for the location based stuff.