Surrounding the entire city is the Outer Wall. There are two entrances in the "normal" world, the Land Gate and the River Gate, as well as an entrance from the Border, called the Border Gate.
The Land Gate is flanked by two solidly-built towers, and is guarded round-the-clock by the Citadel Guard, as well as by formidable magical defenses. The Land Gate is open from dawn until dusk. Otherwise, the Gate remains closed; only those in the posession of a special pass can have the guards open the gate for them during the hours of darkness.
The River Gate is a waterway which leads into the city proper; it is guarded by both a iron grate above the surface, and a magical barrier below the surface. It ends in a series of docks, and is more like a reservoir of water suitable for docking river barges than anything else. The Citadel Guard watches this passageway as well, both from the docks themselves, and from small two-man patrol boats. On the river itself, near the gateway, is a large floating platform, the Customs Barge, also manned by the Guard. From dawn to dusk, it is also populated by bureaucratic functionaries who inspect cargo, impose taxes, and so forth. Entrance or exit through the River Gate is not permitted in the hours of darkness, save for those with a special pass; other boats can tie up at the side of the riverbank but are not permitted to dock.
The Border gate is beneath the city, below the Land Gate. The guardhouse structures which protect the Land Gate extended into the subterranean depths to serve a similar purpose for the Border. An underground river flows beneath the city, coming out of the Border, so there are limited dock facilities as well, though only sufficient to load and unload cargo. This Gate is also open from dawn until dusk, and there are double sets of gateways (both magical and mundane), allowing enemies to be trapped between them. It is heavily guarded, and passage is not permitted during the hours of darkness except by royal writ or in the case of dire emergency.
The Outer Circle (the buildings closest to the Outer Wall) is a mixture of warehouses and cheap housing. It is followed by the Market Circle, which contains the vast majority of commercial ventures in the city. Beyond this is the City Circle, providing housing for the city's middle class. Then, there is the Wizard's Circle; it contains the artistic, cultural, and magical places of note within the city, including the University. The innermost circle, the Inner Circle, consists of palatial estates and much greenery, and is home to the wealthiest city inhabitants.
Every Circle is informally divided into a variety of districts. Buildings of roughly the same purpose are generally found next to each other; for example, there is a Weaponsmith District at two o'clock in the Market Circle. Directions are generally given by district, clock hand, and circle.