Geonames is a crowdsourced database of geographical names for places. Essentially a crowd-sourced gazetteer which is available for free. A very cool resource. But what really attracted our attention was the map of the density of the features in their database. The dark spots in the map below show places that have very few place names. These are largely uninhabited areas.
BUT geonames also notes that "India (0.0114) and China (0.0113) have surprisingly few GeoNames features compared to their high population density."
Yet another example of the varying density of geo-tagged information on the Internet.