China–Vietnam border

The border between China and Vietnam is the line that limits the territories of China and Vietnam.

The land border measures about 1281 km. It starts at the Tripoint with Laos , and goes to the Gulf of Tonkin , passing in essentially mountainous areas inhabited by ethnic minorities. Whilst both sides agree on land borders, the territorial dispute over the Spratly and Paracel Islands has left maritime borders between the two nations undefined.

In several areas, the land border between the two countries runs along rivers. In particular, the border follows the Red River on its section from the mouth of the Longbao River (near Wudaokou village in Hekou County) to the mouth of the Nanxi River (between downtown Hekou and Lào Cai. The lower sections of the Longbao and Nanxi are border rivers as well.

The border between China and Vietnam (which then part of French Indochina) was demarcated pursuant to the Treaty of Tientsin (1885), after the end of the Sino-French War.

A number of crossing points for vehicular and pedestrian traffic operate on the border. There are two railway crossings: between Hekou and Lào Cai (where the narrow-gauge Kunming–Hai Phong Railway crosses the Nanxi River over a bridge), and between Pingxiang and Đồng Đăng (Friendship Pass), where standard-gauge trains can cross the border on the Nanning-Hanoi line.

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Wikipedia