The process for creating nearly instant walls in any version of Minecraft is very simple. This can be done in survival or creative.
All you need are 3 things;
1.Some type of block to build a staircase of blocks with.
Step 1: Build a Staircase
Build a staircase, over water or land. It works best with single steps, ie; 1 up 1 sideways. You can try other methods but this works.
Step 2: Pouring Lava
pour the lava NOT on the top step but one or 2 below it.
Step 3: Wait for Touchdown!
Once the lava has completely touched down everywhere, you are ready for the water...
Step 4: Pouring Water
Now pour the water on any step above the lava.
You can leave the lava in place or not. It will make obsidian from the source block, don't forget to take your diamond pick-axe if you're in survival mode.
Step 5: Cooling Tower
Once the water has cooled the entire tower, just remove the source block of water with a bucket or displace it by putting a block in it's place. Here I used yellow wool block I customized in the Darklands texture pack.
Remember; sometimes lava inside the tower will never go away. For some reason it leaves new source block, esp. in ps3 version of the game. You may want to experiment with towers for this reason, since larger towers might have this glitch more.
Finally you're done!
You can chop out a layer of blocks walking down to make it safe. Making halls inside ? Careful about that residual lava!
This CAN be done making turns in the walls/ staircase. You can make a box then tnt the top off to level it out. This is very amusing for maze building and roller coaster type minecart creations.
*Note; if you jump off any altitude with a minecart under you, then get out just before it hits the ground, you will survive the fall based on the height you left the minecart.
mikefromspace on youtube : )