The Mining worlds exist so that players have places to harvest materials from without having to worry about ruining the landscape or taking away valuable resources from the home worlds. The Mine overworld, its nether, and its end dimensions are regularly reset with a brand new seed, so there is a constant supply of new resources. In these worlds, it is not possible to set homes or make claims.
Do not build structures or leave items here that you are not willing to lose.
There is a portal at spawn that will bring you to a random location in the Mine overworld. Alternatively, join with the following command:
During your time mining, you may encounter Cavetale Dungeons. These are player-built structures that contain blocks and items superior to those found in vanilla dungeons. While custom dungeons may be randomly stumbled upon while adventuring underground, a surefire way to locate one is to right-click with a compass in hand. Depending on your depth underground, you will see a message in chat that either alerts you to dig deeper or notifies you that a dungeon has been located.
Since this world has a special utility, other than the building worlds, a couple of restrictions apply.