The city is surrounded on all sides by a truly nasty mountain range. It sits at a high altitude (around 5,000 feet). It’s most compelling and obvious feature is it’s waterfall. A number of small to medium mountain lakes and waterways all drain into the Tunya River which hits the city shortly afterwards. After entering the city, the river splits into three branches (the Tunya, Oa, and Mosi) that snake through the city. Shortly outside the city, all three spill over a drop in spectacular 5,000 foot drop to near sea level. Other than some truly nasty mountain crossings and a mile-high cliff, the only way in or out of the city is provided by an enchantment on the rivers. Any boat on the river experiences “down” to mean “towards the water”, which all sticks to itself on the way down. That is, you sail up and down the waterfall. (by convention, Tunya is up, Mosi is down, and the Oa branch in the middle is basically the city’s toilet.)
The city is old. It wasn’t built by its current inhabitants (50% human, 40% random mix of the other civilized races, 10% ‘other’.) but rather was found about 250 years ago, right around the time the last great human empire was falling. (The fall of the Nerath empire is central to DnD 4E canon. The member races of that empire are now the “civilized races” and are the core PC races: Dragonborn (give a 14-year-old boy the name of that race, ask him to describe it and this is in fact what you’d get), Dwarf, Eladrin (think “High-Elf”), Elf, Half-Elf, Halfling (cough-hobbit™), Human, and Tiefling (think Demon-people. Tail, pointy teeth, glowey eyes, etc).) An intrepid adventuring party was trying to climb over the mountains, found the city, and reactivated the long-dormant enchantment.
The original builders are unknown, but generally seem human-scale. The found city was mostly alabaster-white stone ruins whose grace and strength can’t be duplicated today, and has since been rebuilt with timber and local stone.
The city mines the mountains and is trades with the farmers on the plains below. Also, the river goes pretty directly to the sea which is not that far away, so a lot of trade comes up and down the river (literally!). The city is in fact a major economic power. As you can imagine, with that economic and racial mix, the city is pretty… lively. Think Mos Eisley, but not as wretched, and more a warren than a hive. Plenty of scum and villainrey to go around, though. And this has been exacerbated by some large precious metal strikes by the dwarves working the mountains and the boom it’s brought over the past decade or so.
The city guard have tried to expand to keep up with the city’s growth and its concomitant burgeoning criminal class but have been playing a lot of catchup. Tossing a whole other bag of cats into the mix is the city’s nobles (descendants of the modern city’s adventuring party founders…. or finders as the case may be), who actually are pretty wretched, indeed. And to top it all off, mountain hideaways, antebellum dungeons from the city’s original life, things washing down the river from out of the heights, and networks of catacombs riddling the cliff’s heartstone are always ready, willing, and able to give life that certain little extra je ne sais quoi… perhaps by ending it with a wet, sizzling sound, and the sound of screams fading into the distance.
Lt. Petrov has managed to squeeze together just enough political clout, favors, money, blackmail-leverage, and public visibility to put together his long-dreamed-of “Specials Unit”, modeled on the original Founding Party. These will be the guys charged with Getting Shit Done- with special dispensation exempting them from most “red sealing wax” (paperwork). If a drunken ghost-wizard is dropping property values in the Highcreek district by making all the marble in the area sing “A Tiefling’s Tail (Is Twice As Stiff!)” to all hours of the morning, you send in the Specials. If the Lord-Mayor’s wine cellar has been robbed of all six barrels of Gral Hammerbrow’s Signature Single-Malt by a platoon of hobgoblin sapper-thiefs, you call the Specials. And if a flaming whirlpool of hellish shadowice forms in your attic, but simply refuses to pay rent or kick in for beer… well, you get the idea.