Sword and Sorcery (5e)
For nearly the entire history of the city its inhabitants have mined and expanded the natural caverns under city to collect more and more of the natural gas. They use it for heating and to power their street lamps.
During this time they have also converted many of the older sights into burial catacombs. Also in these caverns resides The Mechanism. A great, complex machine of ancient origin which is powered by the natural gasses and rumored to be tied to the very fate of the city.
A decade ago Gnomish refugees began appearing in the very heart of the city near the rift. Fleeing from horrors of the Feywild they were given sanctuary and their own enclave with in the city. Since their arrival the families have discovered that the gnomes natural inquisitiveness and mechanical aptitude could be put to great use.