I'm surprised that there seems to be no extension that allows you to put a pin on a world map and open a thread there.
You do not have to create categories and subforums, just put a pin on the map and write a thread.
Every visitor should be able to do that too.
This extension / portal would be extremely flexible.
For example, for information about restaurants, free swimming lakes, barbecue areas, free fruits, good places for communication guerrilla etc ..
You can also retrofit it for many existing forums.
Many existing forums have topics that could benefit from such a feature.
Is there such an extension / portal? If it does not exist for phpBB, is there such a thing for another forum script?