Friendship Pass is a pass near the border between the Chinas Guangxi and Vietnams Lang Son Province. This is one of the busiest border trading points of Vietnam. During the Ming dynasty the pass was known as Zhennanguan (South Suppressing Pass). In 1953, its name was changed to Munanguan (South Watching Pass). In 1965, it became known as Youyiguan (Friendship Pass) as communist China and communist North Vietnam had closer political, military and economic ties.