Lóngzhōu

Longzhou lies on the upper Zuo River near the border with Vietnam. Its river and mountain routes connected Guangxi with the Vietnamese interior, while hereditary native chiefs governed the district. In 1725 the Qing divided the old native prefecture into Upper and Lower Long jurisdictions. Merchants could travel by boat through Ping'er Pass toward Lang Son, although Qing regulations restricted where they could trade across the border.