evidence: Known as the Yalu River (鸭绿江) to the Chinese or Amnok River (압록강) to the Koreans, this 790km long river runs along the lower half of the Chinese and North Korean border from Mt. Paektu down to the Yellow Sea. [...] What is the Yalu River? It is a 790 km river that runs from Mt Paektu all the way down to the yellow sea. It also forms a natural boundary between China and the DPRK. There are many islands in the river, which were settled by treaty between the two countries. Unlike other maritiem borders the waters are considered open to both sides. At many points of the border the countries are only sperated by a few feet. In many ways visiting the Yalu River offers one of the most authentic views of North Korea.