ProFantasy has an entire suite of software dedicated to creating worlds, cities and dungeons. Although a bit pricey, the software is very detailed and puts the creative control at your fingertips to immerse your players in a diverse world.
This is a really nice online based software with a Pro version at $5 a month or $25 a year. Make your World, Kingdom and Cities in great detail. In order to get off to a good start, I would recommend watching a YouTube video or two.
This software is available on a one time purchase of $29.99. It looks pretty good and many images of user work can be found on the official reddit for Wonderdraft.
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