Bat's Folly: The farthest point from the Light, near Ghosthill, Bat's Folly was the fourth and last gate. Built by a mad crusader in a dark black cape, this fortified mansion is said to corrupt the guardsmen stationed there; that's probably just a rumor, though.
Bladeshore: On the far side of the Great River lies Bladeshore, the third gate. The Light Brigade's smiths work here in a great furnace, and the walls of the fortress are covered in weaponry. Also houses the Light Brigade Barracks.
Commerce District: The main sales and manufacture area, it uses a strange combination of man-power, steam technology, electricity, and magic to produce a wide range of goods.
Dragonkeep: Past the Goblin Market lies the castle Dragonkeep, the second gate. Forged from the bones of the last true Dragon, it is an eldritch place, home to the Light Brigade's magical laboratories and training school.
Eternal Spring: The primary water source for the City, the Eternal Spring sits almost directly under the Light and gives birth to the Great River, as well as numerous other small streams and rivers.
Gardens, The: The food source for most of the City, this massive complex of gardens, parks, and farms lies in the center of the City, surrounding the Eternal Spring under the Light.
Ghosthill: The massive complex of cemeteries, crypts, and catacombs used to bury the dead of the City. Severely haunted, it lies between the Spires and Bat's Folly.
Goblin Market: The other major sales area in the City, the Goblin Market sells a variety of strange, unique, and bizarre items for a variety of strange, unique, and bizarre prices.
Great River, The: This river flows from the Eternal Spring and splits into two major branches, separating Bladeshore from the City proper.
Light Brigade Barracks: Dragonward of the Bladeshore, the Light Brigade Barracks houses the volunteer corp that trains to protect the City from Darkness.
Owlwatch: The oldest gate, Owlwatch is the planing and logistics center of the Light Brigade. This fortress holds the Brightscopes, magical viewing devices used to look into the Darkness.
ShadowScience Inc.: Holding one of the few power generators of note in the city, this company seeks to fuse science, technology, and magic to harness, control, and destroy the Shadows. They're housed not far from the Goblin Market. Their mission statement is to defeat the Darkness once and for all. And to make a profit. But mostly defeating the Darkness, right?
Spires, The: A massive living complex in sky-piercing towers. Generally a nice place to live... just watch your step.
Undercity: Near to the only dark place in the City, this maze of rooms, caverns, chambers, and so on lies under the City proper. Home to outcasts, thieves, and the semi-monstrous (especially those... allergic to light), it's a dangerous and wonderful place. Also, it'd be a great place for the Shadowed to attack, if only they had a way in, you know?
Wall, The: The triple-thick holy blessed steel-and-concrete-and-dragon-bone wall circles the City in it's entirety. At the cardinal points lie the four gates, though these aren't really gates in a strictest sense, since nothing gets in or out. Usually.