Are you concerned about current instability in the world? Thinking that Yellowstone may erupt and ruin our day sometime soon? I have a solution for you. It's a community of survival bunkers in a remote part of South Dakota.
If you're looking for a different home building idea, it doesn't get much more "different" than this. A dude in Washington state decided he wanted to build a tiny house that looks like the lunar lander. He succeeded in a big (but tiny) way.