If seclusion is what you're looking for, then I have just the place for you. Try Linfen, in Shaanxi province. Pretty sure you won't find an over excessive amount of westerners there.

Of course, if Linfen doesn't turn out to be your cup of tea, there's always tranquil Urumqi. Here, you can enjoy a splash of two different cultures as both the Han (mainland) Chinese and the Uyghur (Muslim) reside together in harmony.

There is one other option, if you really want to witness all the culture of China, with little to no English speaking foreigners; try Markham, Ontario.