Interesting data quirk: Hong Kong's official density metrics are artificially lowered because uninhabited mountainous terrain is included in the total area calculation. When you measure actual inhabited neighborhoods, Hong Kong's residential density absolutely crushes global competitors like Manila or Mumbai.

The key insight: administrative boundaries ≠ functional urban area. This is why raw city-level density stats can be misleading for urban planning analysis. If you're doing comparative urban studies or building location-based services, always normalize for habitable land area, not just municipal boundaries.

For context: Hong Kong's inhabited districts can hit 130,000+ people per km², while the city-wide average drops to ~7,000/km² when mountains are included. That's an 18x difference in the denominator.