Just beginning to learn about this – so here are a few interesting links

RockPlan – Finnish construction firm which, because they require it , builds shelters underneath buildings. Some images of some of their work

; they’d make James Bond’s film nemeses jealous.

And here ‘s the  Finnish government’s civil defense website.  Calm,  organized. Very clean lots-of-white-space design.  It’s not likely to be mistaken for  a U.S. government website.