Hm, depends. On a 360 world that's only 1000 blocks end to end, you might need to. When a chunk forms (usually 16 x 16), that's that, it's created. If you form all of the chunks in the world, there's nothing that can be new upon updating. So then you'd have to make a new world. But if you haven't formed all of the chunks, then no. This, of course, is only for new, naturally occuring blocks. For actual craftable items? Nope, you can use your old world.

Also, looking forward to seeing your castle!

Now that I've finished this dungeon I've been spelunking (four friggin' days to do it), I'm going to start looking for the site of my new build.

Yeah I've already explored the whole map (that's what I'm assuming you mean by chunks).

It's going to be a while before you see any real work done with my castle lol. It took me about 6 hours alone to partially create the pathway up the mountain.

What's your next build going to be?

Straightforward but time consuming and fairly tense at times. *chuckles* For most of the scaffolding and the dirt laying that turned into the canopy, I had to use the dreaded 'place a block from the block you're standing on' method, which involves creeping to the edge and then placing a block on the side of the block you're standing on without falling off of it. Lots of careful manuveuring required to not fall fifty blocks to your death. You never die in creative, but building things like this in Survival, even without much in your inventory and a nearby bed to spawn at, can still get the heart pumping a bit.

Now I just need to get a Nether portal into the mix and then connect it to my massive Nether rail network for quick travel.

Consider that a tip for anyone on 360 or PC. heh The Nether is dangerous, but extremely convenient for travel purposes between places on the Overworld!

Ahh kay, then yes, when they come out with new types of blocks, you'd have to start a new world in order to get them loaded into your map.

As for my next build, I'm not going to say just yet, as I have no idea if it's going to work. heh But! If it does, I will be sure to post the pictures here! This doesn't have quite as well danger level as the tower or the World Tree, but it will hopefully be just as impressive.

Hold down the shift key.  The one that lets you "crouch" or "sneak".  When you do that it will not let you fall from ledges.

That's unfortunate >_<

Anyways I can't wait to see what you build next. How long does it take you to make these bigger projects?

@theRepublic: That's incredibly helpful! No more falling off edges for me!

That's unfortunate >_<

Anyways I can't wait to see what you build next. How long does it take you to make these bigger projects?

@theRepublic: That's incredibly helpful! No more falling off edges for me!

Just be careful.  One slip of the finger and you are dead.  Happened to me once, and after that I held that key down so hard it made my finger hurt.