World Download Available Here
Update 31.12.17: Housekeeping! Changed and cleaned up a few places in/around the base.

What is this thing?
I started working on this a long time ago when the 1.7 terrain update came out. It's like a 'version 2' of my other underground base I built years ago and there are some strong similarities to it. However, this time I'm trying to make everything even more efficient and much, much better looking (in my opinion anyway :P) and bigger, putting all the new features that had come out since then (especially from the redstone update) to full use and keeping room for the future, something my old base and world were really lacking. My goal is again the same, to build a base which is as automatic and as efficient as possible so that you'll never have to go to the surface to get something from there.

The build
I designed the base to be as future-friendly as possible, meaning that if a large new feature were to be added in the game, it can be added to the base hopefully without too much of a hassle, something that was a major problem with my old base. For example, the 'windows' are 5 blocks wide so that it's possible to hide wiring or whatever in between them. I've also left plenty of space to add new side rooms if needed.

Also, the main rooms are easily rebuildable. They all have the same dimensions. I tried to make the 'machines' that are in them really look like machines instead of making them look 'integrated' in the base, again just so that they're easily rebuildable.