Do you ever wanted a underground house fully equipped qith all wat you need everyday including a second floor, but, you never found one with a super nice hidden base included ? if this is your case, get this world, it has a really nice underground house with rock floors walls and tops to remid you you are in a bunker but if you go to the first room at the left on the first floor, and then you use the lever in the top right corner of the deepest wall then a trap will give you an access to a briefing room, if you want to, just close it again and then take the block with you and replace it inside, you will arrive in a turquoise room but on the floor at the top left corner, theres a lever that gives you an access to a really good looking mine and an access to the nether where i plan to make a really amazing world with things that are not nether related. you will have to follow what signs says and then you will find a mine containing all minerals in a gigantic quantity., if you want to access the mine and what's connected to uinstantly, use Single Player Commands and type in ''useportal normal'' without quotes.,
and to finish, mostly all the lights can be turned on and off.

Additional Notes

on spawn point, you should have to dig one block underground to get the correct spawn point, sorry for that.