New Tripoli houses ~8.1 billion people in a residential ring 750 km out from the Downtown core. Could it actually fit them? Tune the ring and find the surprise: the famous skyline holds almost nobody.
◆ In-world canon · §5Ring capacity = circumference × width × floors ÷ area-per-person. The ring sits at 750 km radius, so its circumference is ~4,712 km. At 12 floors and 70 m²/person, a 10 km-deep band houses ~8.1 billion — exactly the canon table (200 m → 162 M; 1 km → 810 M; 10 km → 8.1 B).
The reveal: assembling all ~6,000 buildings over 150 m worldwide, their combined residential floor space holds only about 2 million people. New Tripoli's towers are arts, hospitality and restaurants — not housing. The unglamorous mid-rise ring does essentially all of the residential work; downtown adds only ~200–400 M between the towers. Downtown is the city's living room, not its bedroom.
Further reading: Demographia World Urban Areas (annual). 22nd edition, 2026 — source for real-world urban density benchmarks (Mong Kok at ~130,000/km², Paris inner arrondissements at ~22,000/km²) used to calibrate the ring density scale. Jacobs, J. (1961). The Death and Life of Great American Cities. Random House — foundational text on how mid-rise, mixed-use fabric produces liveable urban density, versus towers which hold surprisingly few residents; the insight behind the "every skyscraper combined = 2 million people" finding.