Chasm City

Chasm City first appears in 'Consider Phlebas' as a sprawling, inverted pyramid metropolis carved into Phage rock, a marvel of Idiran engineering with terraced levels plunging kilometers deep, illuminated by artificial suns and serviced by vast elevator cores that span from opulent luxury districts to gritty industrial underbelly. Though it plays no direct role in the central conflict of the novel, the city's mention underscores the grand scale of the Idiran-Culture war's battlegrounds. Across the Revelation Space series—which intersects with The Culture through shared universe elements—Chasm City later evolves into a pivotal hub of intrigue and nanotechnology plague in 'Chasm City,' transforming from a static backdrop into a decaying, nanotech-ravaged noir landscape central to human desperation and revenge.