I bought a plugin for the game engine I use and it generates maps based on GPS coordinates. It grabs the terrain heightmaps and data from open street maps, then gives you several options for downloading textures from various sources.

Here's a video of mount ranier I generated with 1 click:

The problem is the plugin costs $90 and after grabbing tons of 4096x4096 textures I got my ip blacklisted for a week from the open source data server.

But it's still kinda neat so I figured I'd share. It's called real world terrain: https://www.assetstore.unity3d.com/#/content/8752