The dungeon (much larger than I could capture in one screen, but the rest is coming)
Notes: The interior is a huge maze. The path under the down arrow leads to a waterfall, which falls onto floating mossy cobblestone, which I'm standing on in the last picture. The dungeon is such so large that I get lost in it sometimes... it's still in progress. The above-ground part is also a maze of sorts, but not nearly as difficult. Also, when you make a wrong turn up there its not a big deal -- you just go to a viewpoint instead of falling into lava or running in circles for 2 hours.
Another note: My aim with this build is simply to have fun by creating the coolest looking thing I can possibly make. So far I'm having a blast. The castle goes from the top-most building point to the bedrock.