BosWash
In William Gibson's Sprawl trilogy, "the Sprawl" is a colloquial name for the "Boston-Atlanta Metropolitan Axis" (BAMA), an urban sprawl environment on a massive scale, and a fictional extension of the real Northeast megalopolis. The Sprawl is a visualization of a future where virtually the entire East Coast of the United States, from Boston to Atlanta, has melded into a single mass of urban sprawl. It has been enclosed in several geodesic domes and merged into one megacity. The city has become a separate world with its own climate, no real night/day cycle, and an artificial sky that is always grey.