This example displays neighborhood boundaries of Portland, Oregon, with each area rendered as a filled SVG path. The map uses a conic equal-area projection configured with a specific center and scale to focus on the city. Data comes from a TopoJSON file of PortlandNeighborhoods, converted to GeoJSON using the `feature` method from topojson. The React app loads the data asynchronously and renders the paths with the `geoPath` generator, applying a teal stroke and fill from the stylesheet.