Yinchuan is in north central China but the two cards we have available were mailed from Beijing: one in 1997 (three stamps are intact, with legible postmarks. Some red postal ink smudging on front, not serious. Grade: 3, $7) and one in 1991 (Seven stamps, of which two are huge, four full postmarks, red bilingual par avion chop, brilliant and extremely desireable card. Grade: 1, $29)