What if there was only one way through a mountain pass, and the city blocked the entrance, and a large civilization was on the other side. Then they could defend it indefinitely.
Isn't that called strategy?
The movie 300 comes to mind. Taking a defensive position between two obstacles should matter, whether it's a defensive city, fort, or just a group of elite soldiers blocking a pass. Kudos to the player who scouted out that pass and had the foresight to build a city there IMO. Though maybe city defense bonuses should be lowered a little, I think they can get up to like 200% right now which already causes headaches.
I really like this UPT thing, can't wait to try it.