What are some underrated or niche communities you use here?

https://feddit.org/c/die_reklame

Now I don't know if it's the same for everyone, but I found this one through c/all Retro commercials from Germany.

https://lemmy.world/c/historyartifacts

@PugJesus@lemmy.world does an amazing job posting interesting things in the historical communities. The above is my favorite so far.