Cities and populations come from the UN World Urbanization Prospects 2025 (UN DESA, Population Division), mid-2025 estimates. Since this revision every country is measured the same way, with the Degree of Urbanisation: a city is a contiguous block of 1 km² grid cells with at least 1,500 inhabitants per km², and at least 50,000 people in total. This makes the numbers comparable worldwide. Municipal borders ("city proper") and statistical metro regions differ a lot from country to country, so neither is used.
Contiguous built-up areas are counted as one city (Tokyo includes Yokohama, Guangzhou includes Foshan and Dongguan). WUP 2025 still lists centres like Shenzhen, Zhongshan, Wuxi or The Hague as their own cities, even where the satellite-based GHSL database merges them into one big blob.
A few names look unusual because WUP names agglomerations after a district or a neighbouring town (e.g. Kasaï-Oriental = Mbuji-Mayi, Xiuying District = Haikou). The map shows the familiar name and the quiz accepts both. Some fast-growing, very dense rural areas in India, Bangladesh and Nigeria (e.g. Hajipur, Kozhikode, Onitsha) count as cities under this method. WUP gives every estimate a plausibility rating, shown on each city's card.
Outlines are the urban centres of the GHSL Urban Centre Database R2024A (European Commission, JRC). Where WUP splits one GHSL centre into several cities, the outline is divided between their centres, so it's only approximate. Places inside and alternative names (including German ones) come from GeoNames (CC BY 4.0). Borders, rivers and lakes come from Natural Earth. Terrain uses AWS Terrain Tiles (Mapzen); the physical and satellite maps are © Esri.
UN data © United Nations, CC BY 3.0 IGO.
