Medieval Fantasy City Generator - procedurally generated, open source
Cartography Assets - free and paid
Dungeon Alchemist - editable, AI-generated buildings, dungeons, and terrain.
Inkarnate - (free version available) create your own terrain and stamps to create cities or terrain features. Recommended map styles:
World maps – Fantasy World, Parchment World
Regional maps – Regional HD
City & Village maps – Watercolor Cities, Regional HD
Battlemaps (including interior maps) - Fantasy Battlemaps, Watercolor Battlemaps
Wonderdraft - one time purchase map creation software. World maps.
Dungeondraft - one time purchase map creation software. Dungeons, towns, exterior areas.
Worldographer - basically Hexographer 2, hexagon tiled world maps down to building maps.
Hexographer - the original, use Worldographer instead.
Dungeonographer - also replaced (mostly) by Worldographer.
Dungeon Painter / Dungeon Painter Studio / Dungeon Painter Studio 2 - the original was flash based, but you can download it. The others are via Steam.
Dungeon Fog (DGNFOG) - custom battle maps, printable or digital.
Map Tool - free, open source VTT, with map creation as well.
Token Tool - free digital avatar builder.
Foundry Virtual Tabletop - one time purchase, rated best by several sites. Here's a map prep tutorial.
Notebook.ai - for writers and DMs to keep up with universes, characters, locations, items, etc. (paid)