Planet Earth 2012

Althought Domes are Shelters, they are not the Ultimate Shelter which would be a place that is below the ground plain and in solid rock. For example a cave in a mountain or a survival, which is a man made structure below the ground plain formed with concrete.

http://www.earthshelters.com/

http://www.1913intel.com/2008/07/12/prefabricated-fallout-shelters/