First choose the number of cities by typing ‘100’, ‘250’, ‘500’, or ‘all’ – then try to achieve the highest population among the top World 50K+ population coastal cities you chose. For purposes of this quiz, coastal refers to cities whose coordinate I use is within a certain distance of a detailed world coastlines boundary shape. Cities must be within 25km for 1M+ pop, 20km 500K-1M, 15km 250-500K, 10km 100-250K, and 5km for 50-100K. Quiz is not timed. Map is only zoomable to a certain level, otherwise city labels would appear.