Harbor City is the first invasion site in Big Willy Unleashed.
Harbor City is featured at the beginning of Destroy All Humans! Big Willy Unleashed and is the original home of the Big Willy restaurant.
Harbor City features many main attractions and stores, among these include Big Willy's, Kluckin's Kitchen, Music House, Disco Inferno, a theatre, a baseball field, a lighthouse, and the docks.
- Harbor City is loosely based off of Staten Island, New York.