Here's a little project I did a while ago and thought it might be worth sharing. It's a set of modular building pieces which are all 6x6x6 blocks and consist of different enclosed walkways and stairs which I used to create an example maze within a pyramid.

The idea was that if you used MCEdit or Worldedit you can copy and place each of the pieces with the tools commands to create whatever design you wanted, they are all designed to link together as long as you align them correctly, i.e. keep to a grid system.

Each of the pieces has various colour coding to help with building as well as navigating (if creating a maze for instance).

When placing each piece if the blue 'lapis lazuli' blocks on the top are touching then the pieces form a navigable path i.e. the entrances/exits match up, this lets you see you design from above without having to go inside and check (see pictures).

When navigating the walls are different colours to aid as markers (to solve a maze for instance), I've added the colours to the list below.

I've included the world save I used with the various buildings and also a schematic of just the building pieces to copy into your own world and use, this contains everything I used to make the buildings in the world save.

The list of pieces with wall colours as appropriate are as follows:

Straight - purple
Corner - green
T Junction - orange
Crossroad junction - lapis lazuli on floor because no walls!
Dead end - red

Small stairs*
Small ladders*
Large stairs*#
Start/End entrance# (also has a custom entrance way designed to be on the outside of a pyramid)
Inner Start/Goal room# (has four entrance/exits each with a different colour on the wall next to them)

* these pieces are double height to allow connection between floors.
# these pieces are double size, i.e. 12x12x6 (LxWxH)

There are also the external building pieces which in my case made up the outside of the pyramid and some vertically aligned (instead of sloped) pieces which I used to create another more abstract building. (See pictures)

I also tried to create the pieces in sandstone instead of stone blocks but stairs on the sloped pieces didn't rotate correctly when using MCEdit, I've not tried Worldedit so it might work with that tool. (see pictures)

Have fun and please post anything you make with these but remember to credit me, thanks.