Modification World Stripper will allow you to completely clean a certain part of the territory in which you are, while leaving only the underground generation. To do this, while in creative mode, press Delete (and to cancel you need to press Insert).
How to install World Stripper Mod
- Download and install Minecraft Forge
- Download mod
- Do not unzip it, copy to C:\Users\User_Name\AppData\ Roaming\.minecraft\mods