Agent Guidance, Natural Earth Populated Places (1:50m)

Curated world city points that join to the countries Collection on ADM0_A3. Join by attribute, never spatially. 113 of the 1,251 points, Istanbul, Montevideo, and Geneva among them, fall outside their own country's generalized 1:110m polygon because coastal simplification pushes them offshore.

Query the GeoParquet data asset in place with DuckDB spatial, read_parquet('natural-earth-populated-places.parquet'), or load it with GeoPandas. It streams over HTTP range requests, so query the published URL directly rather than downloading first. For a quick preview use the thumbnail asset.

Quirks

• The United States capital is spelled with two spaces after the comma, so NAME = 'Washington, D.C.' matches nothing. Use LIKE 'Washington%' or ADM0CAP = 1 with ADM0_A3 = 'USA'.
• South Sudan is SSD here but SDS in the countries file. Remap one side before joining, or Juba, Malakal, and Wau drop out.
• The legacy LATITUDE and LONGITUDE columns diverge from the geometry by up to 0.22 degrees. They are old label anchors, read geom.
• The UN time series columns POP1950 through POP2050 are populated only for the 463 UN-tracked agglomerations, zero elsewhere, and POP2050 is a projection.
• 59 places carry POP_MAX below 1,000, mostly stations and outposts, so population filters silently drop real capitals of small territories.

Coordinate Reference System

EPSG:4326, WGS 84, a geographic coordinate reference system whose coordinates are in degrees. Planar distance functions return degrees, which are not ground units and vary with latitude. For real distances use a sphere or spheroid function, or transform to a projected CRS first. The data asset carries the same code as proj:code.

The same CRS as the countries Collection, so the two overlay and join without a transform. Nearest-neighbour work wants ST_Distance_Sphere, which needs geometry_always_xy set first, as the query below does.

Tested Queries

Capitals per continent, with the country join done correctly.

Nearest city to a point, distance in kilometres.

Related Collections

reference/natural-earth-countries is the polygon companion, same producer and vintage family, joined on ADM0_A3 with the South Sudan remap. Converted from the upstream zipped Shapefile with DuckDB spatial into web-optimized GeoParquet 2.0.