This visualization shows the hierarchical structure of world countries, organized from continents to subregions to individual nations, displayed as a horizontal tree diagram. The data comes from a JSON file containing geographic groupings. Built with D3 v5, it uses `d3.hierarchy`, `d3.tree`, and `d3.linkHorizontal` to generate the SVG layout, while `d3.zoom` enables pan and zoom interaction. Node labels are rendered as text with decreasing font sizes based on tree depth.