Warning: This definition may contain spoilers from any number of Games Workshop novels or source books.
Nuln: The second largest city in the Empire, Nuln forms the trading hub of the southlands, where merchants and artisans from Wissenland, Stirland, Averland and further east to Ostermark and the Moot gather to trade wares and make their coin. North of the city, the Reik is too wide to bridge, and Nuln provides a natural meeting point, as well the only bridge across the Reik. Altdorf may have many bridges, but none of them truly crosses the Reik, only channels, so Nuln has the distinction of the only single-span across the Imperial river.
This is not Nuln's only draw, the city has a well-known University, founded by the Empress Agnetha, whose reputation still draws scholars from away from Altdorf. Appropriately, one of the city's most impressive buildings is the Temple to Verena, Goddess of Learning, which dominates Westway with its imposing collonade.
Nuln is also the location of the Imperial School of Gunnery, where many outlandish designs of seige weapon are tested and forged, and the Empire's finest artillerists are trained. Nuln's standing army benefits from the largest and best-trained corp of cannoneers in the Empire, who are justly feared by Nuln's enemies.
Currently, Nuln is ruled by the Countess Emmanuelle von Liebewitz, noted for her great beauty, lavish parties, extravagant tastes, many suitors and fearsome brother, Leopold.
Gotrek Gurnision and his companion, Felix Jaeger, spent some time as sewerjacks in Middenheim, during which time they had several unfortunate encounters with their arch-enemy Grey Seer Thanquol.(cf. Skavenís Claw, by William King)