The Western Lands are a region of Rathillien that lies west of the Riverland, the Weald, and Bashti. Very little is know about this region, even by the the Four. Mother Ragga's map does not depict it, nor does she know anything about it. The Falling Man known similarly little about the region, though he agreed to go and look for Jame. This lack of knowledge concerning the Western Lands been a roadblock for Marc in his mapmaking project.
Marc says minor houses used to have Kencyr keeps in the Western Lands, as they did in the Eastern Lands, but that no one has heard from them in generations.
There is also once talk of Caldane sending Sheth to some hinterlands, so far from the Riverland it takes a month to ride there. It's not confirmed, but this may be somewhere in the Western Lands.
↑Bound in Blood, "Chapter XI: Equinox", II — "Strangely, there was nothing west of the Central Lands except for tentative scratches."
↑ 2.02.1Bound in Blood, "Chapter IX: Scrying Glass", I — " 'Er… Mother Ragga, I've just noticed: neither the old map nor the new include the Western Lands. I've heard tell that there used to be Kencyr border keeps there, garrisoned by minor families, but it's been generations since we heard from them.' […] 'The Central Lands are my home. Enough goes on there, not to mention here in the north, to keep me busy.' "
↑The Sea of Time, "Chapter XVIII: 'Please' ", IV — " 'Do you even know what’s happened to the Western Lands of this continent?' 'Why?' he said sharply. 'What have you heard?' 'Nothing. That’s the point. If Perimal Darkling has eaten them too, then most of this world has already been consumed by the shadows.' 'It can’t have been. I would know… wouldn’t I?' […] 'Why don’t you find out' […] 'All right. I’ll go look.' "
↑Honor's Paradox, "Chapter XIII: Secrets", III — "The big Kendar shrugged and cast a discontented look at the vacant Western Lands. The Eastern were nearly as bare, with many gaps in between. 'There’s a lot of space left to fill with these little pieces, much of it country which we Kencyr have never seen.' "
↑Honor's Paradox, "Chapter XVI: Tests", II — " 'if you pass, Father has also threatened to demote the Commandant and reassign him so far into the hinterlands that it will take him a month’s hard ride just to get there.' "