Comment by rdl

You can also just buy old (ICBM) missile silos; unfortunately, they are often in pretty bad repair, flooded, and may contain PCBs or asbestos.

http://www.silohome.com/atlas_f_missile_silo_for_sale_ultima... is a particularly nice example of a residential conversion, though.

Moses Lake, WA has a site which got used for ToorCamp, a hacker conference, a couple years ago. http://joachimp.fotki.com/events/toorcamp/page4.html