I just worked a station in China and a Google search of his QTH led me to an interesting website.
EI8IC has put a lot of work into producing maps (some of them interactive) that display prefixes and other info for almost every part of the world. The maps can be used online in your browser or downloaded.
From the interactive map of China, I can see where BA4II is located and get a bit of other info on his province, Shan-Dong.
The Russian map is also interactive, displaying which callsigns go with which oblast.
There are also APRS maps, great circle maps (based on your location), US county overlay maps and many more.
But I find the prefix maps the most interesting since they allow me to see which particular part of just about any country based on the callsigns number and partial suffix.
Check out EI8IC’s website here.