Which is the Largest Country Subdivision?

The Regional World is a simple map of the world which shows the first sub-national administrative regions of every country in the world.

The map uses data from Natural Earth to show only the first level of administrative boundaries for each country. There's nothing particularly innovative about the map or that surprising really. Larger countries tend to have large sub-national administrative divisions and smaller countries tend to have much smaller first level administrative boundaries.

However the map is a great example of two of the biggest problems in mapping; map projections and administrative boundaries.

The Regional World map suffers from the usual problems caused by using a Web Mercator projection. Looking at the map NationalParken in Greenland seems to be the largest administrative region in the world. However the Mercator distortions at the poles means that it actually appears to be a lot bigger than it really is, in comparison to regions nearer the equator.

Wikipedia says NationalParken is the world's largest National Park but doesn't mention whether it is the largest administrative region. It is 375,000 sq miles, so it is huge. Looking at the map, outside of Greenland, Chukot in Russia appears to me to be the second largest admin region. Wikipedia says that 'Chukotka' is 284,827 sq miles in area.

Down in the Southern Hemisphere Western Australia doesn't look anywhere as big as NationalParken or Chukotka. Surely it can't be the biggest first level admin region in the world. Well Wikipedia says that Western Australia measures in at 976,790 sq miles. I think we have a winner.

Or do we? Wikipedia has a handy List of Country Subdivisions By Area, sorted by size. In this list Western Australia is in second place. At the top of the list is the Sakha Republic in Russia, with an area of 1,190,555 sq miles. So where is the Republic of Sakha on our Regional World map? It actually doesn't appear to exist. The map of Sakha on Wikipedia looks suspiciously like the area labelled Chukot on the Regional World map.

So the real winner is the Republic of Sakha or the area labelled Chukot on the map.