I've not used it for myself yet, but I've heard good things. 
[url]https://azgaar.github.io/Fantasy-Map-Generator/[/url]

Alternatively, [url]http://www.hexographer.com/[/url], It can be a bit more hit and miss, depending on what you're wanting, and I've yet to discover how to make it pretty, but it's certainly functional. Though I think it costs to get all the features, can't remember.

Or [url=https://www.youtube.com/channel/UCnlnvC4bOjI6pteFaakBByQ]this channel[/url] might be useful.