: Also, it's odd that it is the only castle we see.
: Interesting, eh?
Not really. White Falls is a fort, albeit not a very big one, the cities of Madrigal and Covenant, and, if we go from the pictures on the map, the other three free cities of the North, are walled. Muirthemne also has a pretty effective set of fortifications. The surface defences of Myrgard include a barrier wall and subsequent gateway, although they've falled into disrepair by the time we see the city in the hands of the Ghols. As for Rhi'anon, it's the biggest and nastiest fortress on the face of Myth, and has a garrison of Trow to boot.
What really confuses me, though, is why nobody thought to built fortresses at Bagrada, Seven Gates and the Northpass. They're probably the three most important strategic positions on the entire planet, so it would be logical that they recieve adequate fortifications.
