Xapros SMP is a chill 18 plus vanilla server where the world is meant to last a long time. I saw around twenty to twenty five players online during busy times so it feels really alive and not empty.
The server is focused on adults who like relaxed survival and big projects. There are no land claim plugins but griefing and stealing are not allowed and you can use a ledger command to check if something goes missing. It keeps the world close to pure vanilla while still trying to stay safe.
Spawn looks really nice and there is a shopping district that uses diamonds so players can trade for stuff they need. There is also an ice boat highway system in the nether so traveling long distances is super fast.
They use Bluemap so you can see the whole world in your browser and plan builds or just explore from above. There is no world border so if you want to live super far away from everyone that is totally fine.
The server runs on strong hardware so the performance is good and they also use Fabric so redstone and farms behave like singleplayer. There are extra advancements from BlazeandCave if you like having more challenges.
It is free to play with no donation ranks or perks. The owners just run it as a hobby because they like Minecraft and want a long term adult survival world.
