User blog comment:Owlfeathers0117/Faction Defense Listings - PLEASE READ/@comment-24142455-20150609164908/@comment-24142455-20150609165120

Almost all non-orbital infrastructure is underground, with the Mars super factories being 2km underground with thick armor. New Carthage and Tribute have surface facilities, but they are for minor things, like small arms and such. Vehicle and ship facilities are mainly underground and armored, but some are on the surface.