The Korean peninsula is located at the eastern end of the Eurasian land mass bordering the Yalu River and the Tumen River to the north with China and Russia, and the East Sea to the east with Japan, and the Yellow Sea with China on the west. Korea is roughly 1,000 km (600 miles) long and 216 km (135 miles) wide at its narrowest point. The de factor boundary between two Koreas is the Demilitarized Zone (DMZ), which is 4 kilometers wide