An undesirable location (city, suburb, neighborhood, shopping center, restaurant, club, bar etc...) usually associated with "Hillbillys", low rent people or things, skanks, or ill-mannered humans and their dwellings...
Collin: "Mom- just had a great job offer from a firm in Joliet, Illinois....great salary and good benifits too. I might consider relocating there from Manhattan.
Collins Mom: "Have you lost your mind?! You have a good job in New York, and you want to throw it all away to live in Joliet, Ill. which is basically known for Joliet state penetentiay, bikers, and cornfields! That place is gross, its positively HILLY-BILLY-VILLY!