This visualization shows a map of Taiwan's counties, rendered as an SVG using D3.js version 6. The map uses a Mercator projection with a custom center and scale, and each county is drawn as a path with a light green fill and gray stroke. Hovering over a county triggers a CSS hover effect that changes the fill to light gray, and a simple tooltip displays the county name via a title element. The geographic data comes from a local GeoJSON file loaded with `d3.json`, and the paths are generated using `d3.geoPath`. The React framework is mentioned in the metadata but is not used in the provided code, which relies on plain D3 selections and SVG manipulation.