They're roads, made from stone blocks and steps.
Yeah, I don't have a lot of buildings, I've been busy with my underground area and the minecart track. Will get started on more buildings next though.
Edit: The basic structure of my barn is almost complete, I decided to go with a wooden roof for simplicity's sake. Now I need to design the interior. Anyway know if you can lock animals in and they stay there?
Thankfully I build things on peaceful. When it's night and it's raining, it gets pretty scary out there.
Also, I have to say the underground view from Eihort is quite nice too. You can't quite appreciate your tunnel network from inside them.
Oh my! I was traveling along my minecart route, when I noticed that I had apparently not made a tunnel exit "cow-proof" since one was wandering around on the track. I hopped off before hitting the cow, but since the minecart travels a bit more, this happened:
Yeah, that's a cow riding away on my minecart and I didn't have any spare ones on me. Minecraft considers a cow riding a minecart to be occupied so the boosters worked as if I was in it. I had to go chase it to the end of the track for minutes to finally get my minecart back.