Lankhemaar, City of High, Dungeons of Forgotten Ages
Reasons might be many for adventurers to ventrue in dungeons below the city of Lankhemaar. Lankhemaar is a city what has grown over generations and generations. When old generations are passed and new kings have come, the city has just been growing. Not by width, but height.
The whole city of Lankhemaar is like a huge mountain the current city with it's current king on top of it all. The city is so high, in few generations it will reach the clouds. Below current citystreets are underground layers, all from previous installments. The deeper you go underground, the further you travel from civilication. The lower the levels are, the more forgotten technology and arts there are amongst strange monsters what dwell there.
Few levels below the current city there are thugs, guilds of prophited black magic, hideouts of master thieves, blackmarkets, outlaws, outcasts, everyone and -thing that doesn't fit for the upper society.
Below these parts there are forgotten dungeons with monsters, treasures, forgotten manuscripts and areas of wild magic in wizards' havens when wizard's been long dead. The deeper you go, more dangers and rewards there are.
Society Around Dungeons
Many find underground levels what are former parts of city their home, as they don't find place where rich and proper people live. Under the street levels of Lankhemaar there are no laws or rules. You can get almost what ever you want there, for a proper price of course, but there is a high risk to loose it all - including your life.
Most of low society, as they are called, just try to survive and live their lifes as good as they can. But not all. Some of them try to make their living stealing or selling goods prophited or hard to obtain. Even some sirs, dukes and earls are rumored to send their agents to buy long forgotten powerful items for a high price.
Thieves are also known to live there. Not petty little pickpockets but rutheless backstabbers and professionals who even can gain access to notable people's homes to steal what they own.
Blackmarketeers sell items what are obtained from lower levels. Some also sell slaves for upper class from the poor living in the dungeons. Also exotic monsters are known to be sold for arenas to use as combatants for the amusement of the upper class or for exotic but dangerous pets to brag about.
Then there are those who travel deep to find what ever is in demand. Ancient scrolls and books, beautiful crafted jewerly, magical items and so on. They usually sell these items for blackmarketeers who proceed to deliver or sell them onwards. They are called graverobbers. They don't rob graves, but dwell deep down the Lankhemaar to obtain what ever valuable or specific item they find.
Mappers are ones who travel usually with a group of graverobbers. They draw maps to sell with high price for those who want to travel deep, but aren't experienced enough to do so. Unfortunaly, usually in mapped areas only less valuable items are left as most precious items are long ago taken.
Sometimes from higher class wizards or noblemen travel with their own group or anonymously with graverobbers for what ever reason they are after. Sometimes to learn, sometimes to personally ensure they gain a certain item or sometimes just out of boredom for an advenure of their life.
Character has his reasons to go for an expedition ventruing to lower levels of Lankhemaar. Maybe he is poor and wants wealth to support his family, or he owns money for some powerful facet. He might be bored duke's son who wants some action into his life. Or he might be a scholar who wants to find something forgotten to gain power or to claim as his invention.
What ever the reasons are, the journey is dangerous equally. And if you survive, the prize can be rewarding. Some go back, out of greed and some don't know any other way of living than put their life on a stake.