First choose any World 50K+ city by entering it and choosing it in the drop-down box. Then, name the largest World 50K+ city in each 100km circle/ring as the rings expand outward from your city of choice. The first circle will include your city of choice as a possible answer if it is the largest 50K+ city in that area.

When you run out of time or end the quiz, you will see the current ring’s correct answer at right (under ‘Answer Stats’ by your coordinates).

For example, if you choose ‘Paris, France’ – you will be shown a circle of radius 100km centered at Paris. Naming the largest city in this circle (Paris in this case) will cause another ‘ring’ of radius 100km to appear outside that circle. You now need to name the largest World 50K+ city in that ring (but not within any previous circles/rings). If a city is not within the next ring of that distance, the ring will keep expanding by that distance until a city falls within it. So if a city doesn’t fall within 200-300km, it will expand to be a 200-400km ring, then 200-500km and so on until a qualifying city is found within the ring.

Too tough?
World 200 Km Expanding Circles Challenge – Choose City