I love it when things accidentally come together
I decided to build a water ladder down to bedrock on my first world, where I already had some stuff built, just to try it out.
I made the ladder, but then I screwed up and built up around the ladder entrace/exit, and then I found I couldn't leave. So I had to dig a staircase up the surface. A few levels up, I found an absolutely beutriful lava fall and waterfall, both right next to each other, and another pool of source lava below. They act as a natural cobblestone and obsidian generator.
Couldn't have designed anything better.
Then I turned right then and kept going up, and once I reached the surface, where should I emerge but almost exactly on top of my second base. So I covered up part of the stairs and then just connected my base to the rest of the stairs. Voila.
Now I'm thinking of getting a ton of glass and building a giant arboretum for my trees, starting from my stone air bridge that connects my two bases.
Edit: (Awful lot of "I" in that paragraph...)
BTW, did you know lava won't hurt your chests if they're sunk in the floor?