City of Madness: The Capital of the Arvorians

Here I admit I am jumping ahead in the campaign ideas for the Arvorians of Norwold, as I originally envisioned in my theoretcial campaign that the PCs would only find this city after a number of previous adventures that gave them clues and maybe outright directions and maps. 

This used to be the Arvorians' third major city until the events around the imprisonment of the Scions of the Outer Dark and then the devestation of the Blackmoor civilization by the Rain of Fire. Since the demise of both civilizations, the Arvorians have hung on in this city more than others. Its true name in Arvorian language is Ursholl'lekti, but humans and other races refer to it as the City of Madness, mostly due to its association with a extraplanar being that drives people mad simply by its mind-twisting appearance. 

Architecturally it is primarily made of black basalt, and the weather tops this off with a sprinkling of white snow, causing a strong visual contrast. There are thousands of small houses perhaps 2 or 3 storeys each dwarfed by the imposing wall towers (#1 on the map), gatehouses (#2) temples (#6 on the map), the wizard sanctums (#4 on the map) and the largest of them all, the central citadel (#7). The port (#3) has some impressive stone piers but is also littered with shipwrecks, so docking here is hazardous. There is also a park (#9) and an amphitheatre (#8)

Most of the city is underground, and is essentially a megadungeon, albeit one that is dominated by a single species. The surface level shown on the map is generally abandoned, though Arvorians do emerge, usually at night. There are also less human creatures that roam the streets. Few natural animals wander here as there is something about this place that scares them and they are probably right. Undead, extra-planar and constructed creatures can all be found in the city, along with a few biological specimens that have escaped their cages or vats. 

The dungeon levels are expansive in all directions, and include living quarters for thousands of Arvorians, their humanoid servants, their monstrous minions and constructs. The first level is accessed via the Great Citadel on the surface (#7 on the map) and contains many trading and residential areas. The second level has numerous natural caverns enhanced by manual and magical excavation to hold great farms of fungi and strange herd animals to feed the humanoid population. Further down below things get more dangerous with crypts and catacombs, libraries and laboratories, barracks and barricades, temples and shrines. There are known to be at least 10 main levels, and dozens of sublevels. There is one particular sublevel with a series of portals that allow instant travel to other Arvorian cities and strongholds, which in turn have their own portals. This has enabled trade, diplomacy and migration between Arvorian cities without the risks or delays of overland travel. 

There are also some smaller, separate dungeons underneath some of the smaller surface buildings, especially the wizard sanctums (#4 on the map) and temples to the Scions of the Outer Darkness (#6 on the map). These are typically only a dozen or so chambers in size but a few do connect via winding passages to the main subterranean levels. 

This city now sits on the northwest coast of Norwold, far north of the Great Bay. There are 2 other cities of the Arvorians nearby - their true names are unknown to humans but they have been given suitably daunting names in the Common tongue. There are suspected to be other Arvorian cities further westward and north into the frozen hinterlands known in common tongue as the Everwinter Lands. As previously mentioned, these cities were founded long before the Blackmoor disaster, and as such would have previously enjoyed much milder climates. 

Based on original by 6inchnails, source

In terms of adventures set in the City of Madness I suggest two different approaches. The first is as a simple dungeon crawl. This is entirely doable although once the Arvorians realise how dangerous the PCs are they will get more cunning and ruthless, using allied and servant monsters en mass to overwhelm the intruding humans. Arvorians may be chaotic but they are definitely not stupid, and will coordinate and cooperate if they face a common threat. I would expect this would suit characters of levels 5-20. The second, more interesting approach, would involve the PCs interacting with the Arvorians non-violently, perhaps as diplomats or traders. This is a similar approach advocated in two modules that deal with the Drow - D3: The Vault of the Drow (1st Ed AD&D by Gary Gygax) and Menzoberranzen boxed set (2nd Ed AD&D by RA Salvatore), and would allow far more exploration of Arvorian culture and overall aims. In fact finding out what the Arvorians intend to do (releasing the Scions of the Outer Dark) could be a major part of this interaction. However, the PCs would be isolated from support or sanctuary, and if things turned nasty they would find themselves underground in a hostile city surrounded by a deadly, intelligent enemy, some of whom could be 25th level. 

The treasure held in the City of Madness has been accumulating for millenia. The Arvorians and their human and humanoid henchmen will certainly use gold and silver coinage for trade and to display wealth. Rarer but still used as conventional wealth are the gems and precious metals - some are recognisable by jewellers of the Known World such as amber, jade and sapphire, while others are unknown outside Arvoria. But the best treasure is the sort that is beyond mere monetary value. Magic items, new spells, arcane knowledge and powerful weapons can all be found - some of it is distinctly Arvorian in style but still understandable to humans, while others, especially the spells, have been passed to the Arvorians by the alien supra-genius intellects of the Scions of the Outer Dark. Such spells and arcane knowledge are not easily comprehended by mortal minds and, while potent indeed, could carry a heavy cost in terms of sanity and souls.