This example visualizes cities that hosted international football games between 2010 and 2020 on a world map. It shows the geographic distribution of match locations using red circles, with the map rendered as a natural Earth projection via d3.geoNaturalEarth1 and d3.geoPath. Country boundaries come from World Atlas TopoJSON, with graticules and a light blue sphere for context. City data is loaded from a CSV file listing coordinates and match counts, while circle sizing uses d3.scaleSqrt. The visualization is built with React and D3 v5, rendering to SVG.