I had based this (rather short-lived) campaign on an old, old thread on rpg.net about a city built around a tarrasque (Which got kickstarted and turned into the Salt in Wounds books). It was short-lived mostly because one of my players (who was the group's normal DM) went and murdered an entire tavern with some Book of Nine Swords crazy stuff and I didn't know how to respond to that.
I apologize ahead of time for the quality being a good bit lower than my usual output. I was learning the ropes. Everything not here has been forgotten or lost.
The City of Anterras
Description of a Map: A river running northeast to southwest. A canyon carved in the red-orange badlands stone.
The River Red cuts through the valley city from north to south. It was originally named so for the red clay of the riverbed, and later for the tarrasque blood that leaks into the southern flow through the Low City.
The Citadel was built atop the great beast, to contain it, to flense and carve and cut away at its flesh. A fortress-abattoir-prison on an island in the river.
The Inner City surrounds the Citadel. Here are found the foundries, butchers and chimericists that make the tarrasque their trade.
The Low City consists of the southern arc of Anterras, and contains within it all the huddled masses yearning to breathe free.
High City contains the rich bourgeois neighborhoods, with manicured parks and beautiful boulevards. The offices of the city government may be found here, as well as the trade houses, courts of law, and university.
The Outer City sits atop the cliff and is reachable only by secret elevator or lengthy staircase. The palaces of the fantastically, obscenely wealthy cling as barnacles to the time-carved stone.
The Riverside slums are split by the Citadel and Inner City, but they are the same either way. Docks and warehouses and teamsters unions and easy access to vices.
The Downs are the undercity, the buried ruins of the city here before Anterras was raised. The parts still (marginally) inhabited are mostly under the Low City.
Smokeside is the northwest quarter of the city, downwind of the foundries. It is a proper Gehennic hellscape, doubling as the plague quarter in times of prion disease flareups.
Breezeside consists of the High and Outer districts. Money = clean air, in Anterras.
Mara-Oversandhill - Halfling trader who does business in and out of the city. Her caravan is the primary means for outsiders to find their way there.
Dr. Percival De Laquoris - Doctor in the plague quarter of Smokeside, runs a clinic there. Infuriatingly deliberate and slow to act. Good standing in the Low City.
Dr. Shil Caster - Percival's assistant. Alchemist. Never takes off his mask. More tolerable to deal with than his employer.
Shady Traw - A shopkeeper in the Downs
Hoskar Torn - Dwarf, lead representative of the Forgeworker's Guild.
Min - Runs a Low City boarding house and post office.
Thud - A domesticated troll in the employ of Min.
Fulwood, Shiv, Osten - Boarders at Min's, foreigners.
Seward the Steward - A steward for the city council offices
Shykana - Orc chieftainess here representing the nomad clans outside the city.
Winras Vadier - Head of the city military, currently preparing for the next crusade against the outside.
Mad Ferbi - A wizard. Lives inside an asbestos suit due to repeated fireball mishaps.