Communities
There are many worldbuilding communities that can help provide feedback and in-depth critique for your setting, map, and ideas. For something more permanent than a /tg/ thread, here are some popular options.
Game Design General originated as a /tg/ thread but has grown into a large discord community that has a side focus on worldbuilding, as it can obviously be an important part of game design.
Worldbuilding Iceberg is an alternative to other chan derived worldbuilding discords. It aims to have an active userbase which provides critique and feedback as needed.
Red Land is a place for worldbuilding, the creation of fictional worlds for works of fiction. The intent is to have projects, to work on and in time finish. It's a place to share your stuff, ask for feedback, understand approaches, and expand your mind. While we have our traditional gaming roots, we are open to anyone who can gel with us. The end goal is a small, active, comfy community where things get done.
Worldbuilding Magazine is a community which produces a digital magazine regularly covering various topics related to Worldbuilding. Their discord is a great place to meet experts and get some tips.
The Cartographer's Guild is a community for anyone who wants to learn the art of mapmaking.
/r/Worldbuilding is a subreddit that allows users to discuss all aspects of setting creation. Great for getting detailed feedback on specific aspects of you world.
/r/FantasyWorldbuilding is another subreddit dedicated to Worldbuilding in general. They have frequent prompts and encourage users to engage with eachother as well as post their own answers.
/r/Mapmaking is focused on cartography and can be a valuable resource when working on a map.
/r/Conlang is a subreddit dedicated to the creation of languages.
WorldAnvil's discord is another popular community for discussing worldbuilding and getting feedback on art, maps, and writing.