Big city: which one is the nearest?
From Rapid City, South Dakota, the nearest city of a million people is Denver. From Wichita, it is Tulsa — not Kansas City, where everyone drives. Every place on Earth has its nearest big city, and our intuition, shaped by roads and state lines, often gets it wrong.
How to play
- A smaller town is pinned on the map, with its name.
- The big cities are shown as dots: every city above the threshold in the zone (one million people, for example).
- Click the one you think is nearest, as the crow flies. The true nearest city lights up with its whole area, and both distances are drawn.
The towns are chosen where it is close: the nearest big city and the next one are less than 40 % apart. At the end of the game, the whole map appears, every place coloured by its nearest big city.
Scoring
100 points for the right city. Otherwise, the closer your pick, the more you keep: 100 × (true distance ÷ distance to your pick)². Picking a city 10 % farther still earns 83 points; one twice as far earns 25.
The map behind the game
In Map mode, open Big cities: choose what a city is, any population threshold (from 20,000 to 30 million people) and a zone (a country, a continent, the world), and the land is shared out between the big cities, each area in its own colour. Click anywhere to see its nearest big city and the next one. Two ways to share: each country with its own cities, or cities from anywhere, borders ignored — then Lille may belong to Brussels.
What is a city?
The answer changes everything. Marseille has 886,000 people within its municipal limits, 1.6 million in its urban unit and 1.9 million in its catchment area. Choose your level, in the game as on the map:
- Municipality
- The city within its municipal limits (France: INSEE; elsewhere: GeoNames, latest censuses).
- Urban unit
- The continuous built-up area, with no gap of more than 200 m between buildings: the city and its real suburbs (France: INSEE urban units; United States: Census urban areas). The rest of the world is being computed with the same 200 m rule.
- Metro area
- Wider: the city and the towns whose workers commute to it (France: INSEE catchment areas; United States: Census metropolitan areas; elsewhere: GHSL functional urban areas with 2025 population).
- Dense centre (GHSL)
- A satellite measure of its own, neither an urban unit nor a metro area: contiguous 1 km² cells of more than 1,500 people per km². Low-density gaps split cities, so Cergy-Pontoise counts apart from Paris.
- In the United States, Seattle's area runs to Alaska; Salt Lake City and Denver are islands that cover the Mountain West.
- In France, with cities of 500,000 and more, Paris's area covers the whole north-west of the country.
- On the whole planet, with cities of 10 million and more, a single city can cover half a continent.
Where the figures come from
France: INSEE (populations, urban units, catchment areas). United States: Census Bureau (urban areas 2020, metropolitan areas 2024). Elsewhere: GeoNames (municipalities) and the Global Human Settlement Layer (European Commission, Joint Research Centre). Distances are measured on the globe, as the crow flies. See the credits.