"Strategically located in the awesome San Juan mountains of Southwest Colorado, this patented steel-reinforced concrete earth home was built to withstand almost any natural or man-made disaster you can name. It is more secure, safe, and functional than any conventional house could ever be, yet still has a level of comfort that one might not expect to find in an underground home."
It is completely off the grid, relying on solar power for all the electrical needs. It has a safe room (i.e., "bomb shelter"), and is hardended against almost anything.
In an apocalyptic mood? Get it now for just $495,000.