This mod adds 2 new dimensions known as the building and cave dimensions which are dedicated dimensions for mining and building
The building dimension is a superflat world with no hostile mobs, allowing infinite space for building
The cave dimension is a giant endless cave full of ores and also full of hostile mobs
Instructions to get to the dimension
To make a portal to these dimensions, you will need to make a teleporter base which is crafted by combining an iron ingot and a ender pearl, then place the blocks in a portal shape like the nether portal

To activate the portals, make a redstone wired enderpearl by combining a enderpearl and a redstone block. Right click the portal with the redstone wired enderpearl to go to the building dimension
To get to the cave dimension, make a diamond infused redstone enderpearl by combining 4 diamonds and a redstone ender pearl, now right click the portal to get to the cave dimension