tenderloin (TEN-duhr-loin) noun
The part of a city notorious for vice and corruption.
[After a district in New York City known for vice, crime, corruption, extortion, graft, etc. It received its nickname from the choicest part of the meat, alluding to the luxurious diet of corrupt police members getting an easy income from bribes. Today, there are Tenderloin districts in other cities, particularly in San Francisco. Another metaphorical term with a similar connotation is"skid row," which has its origin in Seattle.]
"Forbidden from working, they moved in to a seedy residential hotel in the Tenderloin district as they waited for their application to be approved."
-- Joe Mullin; Refugees' Work; The Mercury News (San Jose, California); Jul 10, 2005.