AlmostAnarchy is a semi anarchy vanilla server where you can pretty much do what you want. It tries to feel like Minecraft the way the game was made to be played.
There are almost no plugins so the world feels really natural. Hacks and cheats are not allowed though so you still have to play fair.
The server is small with around three to five players on most of the time and sometimes it hits ten. Because of that people know each other more and it feels like a tight community.
Players have already made some really cool projects and bases. You can explore them or go build your own far away and see how long it survives.
If you want a survival world with surprise encounters and a lot of freedom this server is a good place to join.

