Friendship Pass, located on the Sino-Vietnamese border, has a history of more than 2000 years. It is the only one of the nine customs ports in China, which is still in use today. This is the place where the Sino-French War "Zhennanguan Dajie" took place. Sun Yat-sen personally directed and personally launched the "Zhennanguan Uprising" and other major historical events. The main scenic spots are Zhenguan Fortress, Zhenbei Fortress and Zero-kilometer Boundary Monument. It's educational and worth visiting.