Known as "The Unbreakable City", Bala is a a fortress city built in a matter of months by Queen Ratha. At it's outer permiter is a series of interlocking walls, with baracks, smithies, and market places inbetween the walls. Each inner level of the city raises above the previous one, making it extremely difficult for an attacking force to "climb" to the next level, while it's very easy for defenders to come to them.
In the inner city are terraces of farmland, artificially built and irrigated by the city's aquaducts. More markets surround the city center, where the Palace is located. At the Palace's center is the Central Fountain, a Gnomish marvel that pumps water from deep under the city up to the Central Fountain, and from there, runs through the aquaducts to every part of the city.
What's almost more impressive than the "upper" city, is the underground city beneath Bala. Where the majority of the population live (nobility included), Bala sports enough housing and markets and smithies to support a million people, making it the largest city in the Five Kingdoms.
The "lower" city is a source of pride for the citizens of Bala, as it was their refuge just fifty short years ago. Connecting the lower city to the rest of Kelir are the "undergound highways"; the tunnels used by Queen Ratha to defeat the armies of the other fout kingdoms. They are still used today, both for moving troups and supplies, sending messages, or these days often just for passing news quickly from one end of the Kingdom to the other.