This is an extremely hard book to pigeonhole, so I won't bother doing it except to say it has the kitchen sink, too. 
 So much happens for what ought to be a tale of exploration before building a railroad, the building, the freeing of the enslaved biomonstrosities called the Remade from their long toils, to building of a diverse and growing society. Never mind that there's also the opening, middle, and end of the civil war to end all civil wars in New Crobuzon and along the rails. 
 I didn't expect it to turn so political, but it did, and Mieville's leanings are not only clear, but amazingly complex and muddy at the same time. Grey area? You bet. Delightfully so, and I'm rooting for all the characters and also the characters that are the City and the Iron Council, as well. So much character, so much love. 
 It may be impossible to tackle just how amazingly imaginative the world-building is, but I'll give you a taste of so many golems, flesh trees, Inchmen (omg how amazingly disgusting), the spirals that bring about the grand murder, the cactus men, the insect women, the Victorians, and so many other truly odd and strange people that fill this land and insane spacetime mash of a universe that is, by its own reckoning, still a work in progress. 
 I think we could all spend a couple of decades pouring over these books building no more than a slight working knowledge of the place and its people, and I rather wish I could visit, no matter how freaking dangerous it would be for me. Maybe I'll hire a Tesh priest and thaumaturge myself into some sort of immortal to make my tourism a bit safer. (But only a small bit safer.) 
 What a world! 
 I think I liked the characters and the overall tale of this novel better than both of the others preceding it, or perhaps I was less waylaid by the complexity and the eye-popping wonderful that meets me on every page because I've *been* through the learning curve of the previous two novels. Either way, it was absolutely amazing. 
 Few works of fiction can boast this much sheer density of unpackable information, and the fact that we've got a working story with memorable characters is freaking amazing. :) 
 Everyone ought to have a working knowledge of this landscape, even if they can never be called an expert. (No, not even the author. I think he must have channeled all this from another dimension.) 
 :)