Yonapol

Yonapol, also known as "The Only City" is the most populated city on Iryanka, It is also the most polluted area in the entire Star System.
Yonapol was founded during the Copper Era and reached its prosperous state around the end of the Iron Era.
At first a small settlement under the mountains of Shaltam, it became in a few decades, the largest metropolis on Iryanka even though not any outsider knew about the existence of this city until the end of the Copper Era.