Nanza is the city that developed around and over the Nanza Pass, the sole existing traversable route from the West and South of Ember through the Vesuvius, Agmen Borega, and Malterian mountains to the Great Western Desert and the city of Al Beth in the Malterian mountain range. Originally a secluded border guard station, a trading post and hostel for travellers were added early on in its history as routes opened up to Dah Rein and Al Beth, which lead to Pyricorn Threads into Shadow. Although the pass itself was relatively isolated, the regular passage of traders and settlers to and from Ember allowed for commerce to increase, which subsequently increased the number of people who desired to settle in Nanza. Over time, a small township developed, still watched over by the border post.
The presence of the border guard proved fortunate, for in 139 CY there began to be reports of scattered raids on caravans along the route to Dah Rein. The attacks were hit-and-run, and not easily traced at first, given the few survivors. Members of the border guard began to accompany the caravans, at which point the instigators of the raids became known -- a group of horseback riders wrapped in black caftans and robes calling themselves "The Moonriders of Genesh", apparently after the ghostly white steeds they favored and rode, day or night. The first few attacks on the escorted caravans were turned back sucessfully, but it soon became evident that there were more Moonriders than border guards to protect travellers. The efforts of the guards to protect the caravans were complicated further by the fact that the Moonrider's mounts granted ephermerial powers to their riders, making them capable of surviving normal blows while striking out solidly with their own attacks. Magic and Cold Iron proved effective, but there were few in the border guard that possessed both in any sufficent quantity.
Traffic slowed as the raids continued, though some travellers were still capable of making it between Nanza and Dah Rein. The situation degraded further in 141 CY as reports from Ember agents in Dah Rein indicated that the Moonriders were beginning to mass together for a concentrated push though the city and up the Nanza Pass. It was apparent that they would try to take Nanza, and possibly press further into Ember proper. An Emergency Session of the Privy Council was called, and strategies were hurredly discussed. It was then that a young lieutenant in the Ember armies, one Haruka Arisugawa, proposed -letting- the Moonriders through into the pass; but with some caveats.
Finally, the Moonriders of Genesh made their assault, surging through Dah Rein from the Pyricorn Thread into the mountain pass at the juncture of the Triad, a twisty route that was still traversable by mounted riders and carts. Several token forces of soldiers faced the Moonriders and were injured, escaping on horse or by Local Trump. Confident, the Moonriders continued their advance.
That was when things began to go wrong for the invaders from Genesh. On a command from Haruka, an avalanche was triggered by the mages of Ember (including the Regent) in several key places, which had been set up 24 hours before. The landslides effectively blocked off the pass, boxing in the Moonriders and splitting them up, preventing them from escape. Then from hidden emplacements and Local Trump Gates, an arm of the Ember Army swept in. With a mixture of swords and sorcery, the Emberites slaughtered the Moonriders to a man, leaving none alive.
With the strength and intelligence of the Ember Military asserted, as well as Ember's victory in the battle, trade lines strengthened and the public perception of the Ember Armies improved considerably. In a full court session, Regent Catherine elevated Haruka Arisugawa to the post of Marshal of Ember. Nanza grew as a full military garrison was assigned to the Nanza Pass to prevent such an invasion from happening again, and escorts were increased, protecting the traders. Nanza was officially declared as one of the cities of Ember, and remains so to this day.
(It was rumored that certain members of the city council of Dah Rein were in leauge with the Moonriders, allowing them free passage through the city to reach Nanza, in exchange for a part of the spoils in the case of a successful invasion and a possible expansion of territory into The Triad. These accusations were never proven, but it is a documented fact that Dah Rein was not as damaged by the invading Moonriders as would be expected. As for the source of the Raiders, it was never truly discovered; the going theory is that they were marauders who travelled the Pyricorn Threads. Their home Shadow has not yet been found.)
In the present day, Nanza is considered a remote post, even given its importance. The most travellers have to fear is the occasional bandit gang that hide in the twists and turns of the Pass, who are easily fought off. This is made even more appropriate in the fact that Kyle of Nanza was appointed (well, drafted is probably a better way of putting it) to the position of Watch Commander in 451 CY. A former brigand who had tried to rough up travellers in the Corona, Kyle was captured by the Warden of the Corona, who was impressed by the brigand's skills and pluck (if not his fashion sense). With his associates, Kyle has reduced the perils that can befall travellers.
The City of Nanza itself is made up of tall buildings and towers connecting bridges across the intersection of the pass; from the taller heights, one can see in the distance the Great Wester Desert, the Desert of Darah, and the far flames of the Corona.