King City, California is a small city in central California. Its mayor is the Man in the Tan Jacket.
It is theoretically impossible to reach King City from Night Vale. There are regularly scheduled buses and flights from Night Vale to King City, but these only take passengers back to Night Vale.
Under some circumstances, however, it is possible for Night Vale residents to reach King City. Troy Walsh managed it via unknown means, and Diane Crayton and Jackie Fierro drove there while holding a time-disrupting artifact.
King City residents can reach Night Vale--the Man in the Tan Jacket made several trips while investigating his city's increasing strangeness.
Also, as stated by Old Woman Josie in the Welcome To Night Vale Novel: If you look up anything, and go to searches, King City will be the first to pop up