Fantastic Interactive Map of China

I have serendipitously found an amazing interactive map of China that lets you superimpose a variety of indicators over a 'Google Maps' kind of map of China. The map is consistent with the boundaries of China as of the end of the 20th century (i.e., PRC + ROC) meaning that, except for some borderland areas, it covers pretty much any region that the GM may use as the setting of his or her Celestial Empire campaign game.

Just click here, remove the already-superimposed grid, and experiment with:
 - religious sites
 - minority place-names
 - mountain peaks and passes
 - historical places: Míng garrisons, Qīng courier stops and routes, Míng/Qīng postal stations, exam seats, sections of the Grand Canal, Táng prefectural & county capitals,
 - vegetation

Postal routes and courier stops in Qīng China

Edit 24/02/2016: the interactive map has moved here.