Nuln is one of the greatest cities of the Empire of Man, a grand and smoke-wreathed metropolis straddling the river Reik in the Empire's south. Once the imperial capital in ages past, it remains a place of enormous wealth, culture, and industry, its skyline a forest of foundry-chimneys wreathed in the perpetual haze of gunpowder and forge-smoke.
Above all, Nuln is the arsenal of the Empire. It is home to the famed Imperial Gunnery School, where the state's finest engineers perfect the art of artillery, and its foundries cast the great cannon, mortars, and Helblaster volley guns that thunder across the Empire's battlefields. Where Altdorf holds the throne, Nuln holds the guns, and no army marches far without its output.
The city is sharply divided between its gilded upper districts, where wealthy merchant-princes and the countess who rules Nuln keep opulent courts, and the grim industrial sprawl below, where labourers toil amid soot, poverty, and the constant roar of the foundries. Few cities in the Old World display the gulf between splendour and squalor so starkly. Its great university draws scholars and engineers from across the Empire, and beside them labour the alchemists and powder-masters whose experiments as often maim as enlighten, so that the smoke hangs thick enough above the river districts to turn the sun to a rumour and the crash of the test-ranges never truly falls silent.
For all its powder and prosperity, Nuln shares the Empire's every peril. Skaven infest the tunnels beneath its factories, cultists whisper in its shadowed alleys, and its wealth makes it a prize coveted by every enemy of mankind. Yet its cannon roar on, and so long as Nuln's foundries burn, the armies of the Empire of Man will never want for iron and fire.