The object of this quiz is to place 20 circles of radius 1000 km on the map so that they contain the largest total population.
When you begin you'll be given a 1000-km radius circle centered on the map. Move it using the mouse and click SUBMIT. You will be given a score for that circle corresponding to the total population contained within it based on world population density at https://human-settlement.emergency.copernicus.eu/index.php. Try to complete all 20 circles with the highest total score.
Any INTERSECTING areas are only counted one time, so no population will be counted more than once.
Quiz Takers 
Curious why the second Indian city is Mira Bhayandar and not Thane?
Per typing in Thane on Google Maps, it looks like the eastern part of the city is not on the island.
1) Of the five boroughs of New York City, only The Bronx is not entirely located on islands. I say it should count.
2) While the majority of Hong Kong’s residents do live on the mainland, if you only counted the island population of Hong Kong, it would still make the top 40 overall.
3) Same goes for Xiamen (Huli + Siming = 2.1 million).
4) I don’t believe any part of Zhongshan is on an island.
I want to include cities entirely on islands. Also it appears Zhongshan is entirely on a river island (Zhongshan island).
Geoje(South Korea) is also a city located on an island.
will add, thanks.
Would you consider doing one that’s largest cities above a certain altitude?
it’s tough because largest cities can cover a large span of altitude
Venice is a curious case… the city center is definitely on an island but the majority of the population of the Venice commune is found mainland. A little known fact I think.
Yes, I guess it’s a good criteria.