This server is called Bone Voyage and it has a special community build world. The community world is totally separate from the other worlds so your progress and items do not mix. In this world players are in creative mode so you can just build as much as you want.
To build here you need the Trusted role. You join their discord and make a simple application in the trusted channel. When staff approve you they give you the rank in game and then you can go through a portal at spawn into the community world.
Building in this world is mostly unrestricted. They only use flags to stop griefing stuff like TNT and similar things. You can build alone or with friends and the server plans building events where everyone works together on cool projects.
When a build or a part of a build is finished the staff use worldguard to protect it. That way nobody can ever mess it up. If you are doing a solo project they will protect that too once you are done.
It feels like a place for people who really like building and want a safe creative world with staff watching over it.
