This interactive visualization displays a hierarchical sunburst chart of the ISO 37120 city indicator dataset, showing nested categories as colored arcs that users can click to zoom into deeper levels. Built with D3 v5, it uses `d3.partition` to compute the radial layout and `d3.arc` for path generation, with smooth 750ms transitions handled by `transition.attrTween` and `d3.interpolate`. The color palette is generated via `d3.scaleOrdinal` with `d3.interpolateRainbow`, and labels are rotated and positioned using `labelTransform`. Data is loaded remotely from the Observable `@observablehq/flare` library.