There are several of the old missle silos near here, several years ago you could but them for peanuts. One has been converted to a training facility for divers, others have been converted to nice homes. Recently there was an article on one of them in the local newapaper, the owner said heating and cooling cost next to nothing and it didn't cost much more to convert than than having a good storm shelter built.
I thought it was kind of silly at the time but today I wish I had taken a closer look.