City fingerprint

Every city has a fingerprint: the pattern of its streets. A grid, a star of avenues, a knot of lanes around an old centre, a city squeezed between a river and the hills. Here you see only that fingerprint — no names, no borders — and you drop it on the map where it belongs.

Choose a set

• France: cities 73 cities
• Europe: cities 1,069 cities
• United States: cities 337 cities
• World: the 300 largest cities 300 cities

How to play

1. Study the streets. The city appears as its street network alone, inside the red outline of its built-up area, major roads drawn thicker than side streets.
2. Drag it onto the map and let go where you think it is. Close enough, and it snaps into place and becomes a named dot.
3. Stuck? Clues come on their own, or put the city back in the pile for later (−10 %).

The clues

1. Water: the rivers, lakes and sea around the city appear — often the biggest giveaway.
2. Neighbouring cities: the view zooms out to the six nearest large cities, shown as dots sized by population.
3. Their names, one by one.
4. Finally the city's own name, and ten seconds to place it.

What to look for

• A strict grid usually means a city planned in one go: most of the United States, Barcelona's Eixample, Turin, Mannheim, Latin American capitals.
• Rings and radiating avenues mark old European cities that grew outward from a walled core: Paris, Moscow, Vienna, Milan.
• A river through the middle narrows things down quickly; a city cut in two by a wide estuary or a strait even more so.
• Streets that stop dead along a smooth line often mark a coastline; streets stretched in long fingers follow valleys between hills.
• Size is to scale: a sprawling fingerprint is a metropolis, not a market town.

Where the cities come from

Built-up areas are the urban centres of the Global Human Settlement Layer (European Commission, Joint Research Centre); streets are drawn from OpenStreetMap through OpenFreeMap. See the credits.