Formerly Changchiakow historic town and trade
centre in Hebei province, China, 160 km/100
mi NW of Beijing, on the Great Wall;
population (1990) 1,100,000. Zhangjiakou is
on the border of Inner Mongolia (its
Mongolian name is Kalgan, `gate') and on the
road and railway to Ulaanbaatar in Mongolia.
It developed under the Manchu dynasty, and
was the centre of the tea trade from China to
Russia.