For all practical purposes, the northern edge of the world is the Jorvyll Mountains. The Arandellion Moors do lie beyond, to the north, but their worth is clearly quite limited, and many cartographers do not even include the Moors on their maps. Others argue that the Moors are really just plateaus within the Jorvyll Range, and that the Worldwall is actually a part of it too. (Whether or not the Worldwall is an orthogonality boundary is a question for the geomancers that I won't venture to touch with an eighteen-and-an-eighth-nanit-stick.)
The Jorvyll Mountains are differentiated from the Sarfelogian Mountains primarily by their attitude (yes attitude, not altitude). The Sarfelogians are a much calmer, more peaceful and helpful range of mountains, while the Jorvyll are rough, nasty and brutish. Yesticale worms, wormwood, fefferberries are all products of the Jorvyll, while Pziqq trees and mountain meadows are found in the Sarfelogians. The Jorvyll region is also blamed for the dance craze of the Zot.
The Shrigure Gradient marks the boundary between the Sarfelogians and Jorvyll, although there is presently no known method for locating this boundary. One is hiking though a pleasant mountain meadow in the Sarfelogians, and suddenly the whole environment changes and the surroundings are noticably ominous and hostile. It may be possible that the boundary could be identified with the judicious use of a supranatural luminescence meter. However, at present, this remains a theoretical concept, and hikers traveling close to the border are cautioned to be careful in their travels.
The difficult terrain of the Smrecklit Range of the Jorvyll was an ideal location for Agarttha to be founded, as it kept the Blasphemers who founded it well out of everyone else's way, and the inhospitable character of the region also served to keep their numbers down. How they managed to smelt enough bronze to build their towers is anyone's guess.
Keglacians once settled the edges of the Jorvyll, but in the past century, this entire culture has migrated southward. Due to this, they are not considered proper candidates for discussion in the topic.
--Brother Arfrus 15:55, 29 Jul 2005 (EDT)