Wanderlust World Wanderlust World London (Greater London): 1,572 km² (607 sq mi)
Paris (City Proper / 20 Arrondissements): 105.4 km² (40.7 sq mi)
Paris Métropole (Metropolitan Area): ~2,850 km² (1,100 sq mi)
London's administrative area is ~15x larger than Paris's city proper. However, the Paris metropolitan area (including suburbs like Seine-Saint-Denis, Hauts-de-Seine, Val-de-Marne) is larger than Greater London and comparable to the London Metropolitan Region (~8,382 km²).
Definitions matter: "city proper" vs. "urban area" vs. "metro area" yield different rankings.