2,980 large and medium airports with scheduled services from OurAirports.
Each region is closer to a particular airport than any other.
This partitioning of the sphere is called a spherical Voronoi diagram, and was calculated by
d3.geo.voronoi, which is currently under development.
The point at … is furthest away from any airport in the above dataset; … from the nearest three airports.
There are in fact airports on Antarctica, but they are not classed as medium or large, and do not have scheduled services according to this dataset.
… at … is the most remote; from the nearest airport, .
Related: Mike Bostock’s U.S. Airports Voronoi.