CaveMC is a semi anarchy survival server with an enhanced vanilla feel and the whole overworld is underground. There is no surface at all so you live in caves forever and the world is packed with biomes resources and structures.
Season 2 is out with a fresh start and a bunch of additions. The server says survival is brutal and you have to be smart to make it.
There is also a big new thing called the Wasteland Dimension. It adds new gear mega structures to explore and mysteries to figure out. It also brings its own currency and a new player driven economy plus a new spawn and a custom generated map with special features.
Cave Only Semi Anarchy Season 2
GG.MINEWIND.NET New Server IPAnarchyMC No Rules No Resets
I found AnarchyMC and it is a straight up anarchy server with no rules. There is no anti cheat so it is a rough place where anything can happen.
The map has not been reset and it is about 1.5 years old. Spawn is already pretty griefed and it has that lived in history feel.
If you want a long running world where you can do whatever you want then this server is basically that.GG.MINEWIND.NET New Server IP