I know South Korea has a pretty large military when you factor in the reserve troops, close to 4 million troops. I know they have a pretty modern military including weaponry on the border designed to attack artillery, shoot down shells, shoot down missiles, etc.
But I once read a short article about how Seoul itself has been designed to be heavily fortified against an invasion. The only thing I remember from the article is that the major roadways are designed so that they can be closed off in case of a major invasion by demolishing concrete barriers above the roads.
But in what ways is Seoul designed to withstand an invasion? Are there special military installations, equipment and tactics there you wouldn’t see in a place like NYC?
Is Seoul designed to become a fortress in case of invasion? If so, how?