True the only still kind of used ones are the command bunkers, and even they are really outdated. >Others, such as the Castello mentioned by /u/nix23 are used

True the only still kind of used ones are the command bunkers, and even they are really outdated. >Others, such as the Castello mentioned by /u/nix23 are used as temporary barracks for troops, but don't have an actual defensive function any more. But temporary is not quite right when it's used for then first 10 weeks of recruiting school ;)