A world map showing cities with population greater than 50,000. City data from OpenStreetMap, querying all features with place=city.

Gray dots are all the cities in the input data. (Cities in India are missing from this dataset)

Blue and white dots show biggest cities with all their smaller neighbors (within a given radius) filtered out.

Country boundaries from World Atlas TopoJSON, polished for visual style. (That part forked from Sized Points on a Map)