minitsteer

Underground houses carved from natural rock formations local to Kandovan, Iran
These low-energy houses are actually 700 years old, are available for rent.

Read more: 700 Year Old Underground Cave Homes For Rent in Iran Inhabitat - Green Design Will Save the World
http://inhabitat.com/2010/08/03/700-year-old-underground-cave-homes-for-rent-in-iran/