Jindazhen is a land to the west of the Yamani Islands. The Yamanis have to fend off attacks from them with some regularity. It has only in the novels by a small mention in Page so far.
Tamora Pierce based Jindazhen on China. The literal translation of the Chinese syllables would be "gold big needle" or also "gold big town", which wasn't intended by the author. Tammy just chose the name because it sounded right. Its counterpart in the Emelan Universe is Yanjing.