Hours stretch into days as you pass through mile after mile of fetid swamp, watching and hoping for some vision of civilization. At noon of the second day, you catch a glimpse of your first sight: the high peak of some vast tower rising out of the muck miles and miles away to the southwest; an hour later, when you catch sight of it again, you see now that it is in fact a colossal ziggurat of unimaginable and incalculable size. It is only then that you realize what must lie beyond the swamp; beyond this stinking and insect-swarmed terror can only be the fabled First City, great Ur-Hadad, the jewel, tarnished though she may be, of mankind's collected realms. Your head abuzz with dreams of the wonders and splendors, treasures and pleasures that this great city may offer, you hasten your pace at the oar, each row bringing you closer to what may lie inside the First City's high walls.
It is nightfall before your first glimpse of the Usud Usal, a high wall that separates the city proper from the trackless swamp beyond. Here, built up against the wall like a lean-to shed, the village of Mustertown huddles close to Ur-Hadad's westernmost gate. The city proper may be rock and plaster, marble and metal, but Mustertown, shelter for the commoners, rogues and miscreants deemed unworthy for entry to the great city, is a moldering mass of crudely-cut and salvaged wooden planks that swell with the surrounding humidity. It is here, at least, that you may finally find some respite after your long ordeal in the harrowing swamps.
In my Game of Taps campaign, the First City of Ur-Hadad fills the role of "campaign mega-metropolis," like Waterdeep, the City of Greyhawk, or Goodman Games' own Punjar. I plan on borrowing liberally from these other metropolises as makes sense, as well as from Purple Sorcerer's "Sunken City" series (I friggin' love the idea of Mustertown and am importing it and the swamp surrounding it whole cloth). I wrote this little bit as the players' first glimpse of the First City, but a lot more information will make it into their hands and yours as it is written.