This example displays a world map with circles sized by city population, showing all cities with populations greater than 50,000. The visualization uses React for rendering, combined with d3.v5 for geographic projections and data handling, including d3.geoPath to draw country boundaries and graticules from World Atlas TopoJSON. City coordinates and population data come from Simplemaps, with circle size encoded through a d3.scaleLinear function. The map uses a light, polished color scheme with semi-transparent teal circles over gray landmasses.