There are probably some people who have heard of GauGAN, a program developed by NVIDIA.
It is an AI-powered engine which makes landscape, of your choice, based on millions of photos of geography.
It works like paint, you paint some things on it, click on a button, and boom it becomes a landscape.
It is an online program.
Right now, GauGAN is open for demo.
This means that y'all have access to making unique landscape with tools such as clouds, mountains, hills, water and rivers, to perfectly match your mapping.
Note that GauGAN is AI, so it may be confused at some things you draw, for example if you detail it too much.
Note that this is not an advertisement, but rather a reminder for people wanting to create unique landscape eventually for a wiki article.
I actually made this landscape. This is a demo for some local hills and mountains.