This interactive map visualizes aggregate course view counts by country using a Mercator projection rendered in SVG. Users filter the data by course category via a dropdown menu, which updates the circle sizes representing total views per nation. The visualization loads geographic boundaries from a TopoJSON world atlas and CSV data containing viewer locations and course enrollment metrics. Built with React, the example uses d3.geoPath for map rendering, d3.scaleSqrt for proportional circle sizing, and react-dropdown for the selection interface.