Tumangang-tong (Korean: 두만강동) is a neighbourhood in Sonbong, Rason, North Korea, near the China–North Korea–Russia tripoint[1] where the borders of the three countries converge.
The Korea Russia Friendship Bridge connects Tumangang and Khasan and is the sole crossing point on the 17 km (11 mi) long North Korea–Russia border.
[2] A train connects the city on the Vladivostok - Rasŏn railway line.
In Tumangang, there is a station linking Russia and North Korea, thanks to a railway bridge crossing the Tumen River.
The railway between the two countries was built during World War II to transport Soviet troops and weapons to Korea to fight against Japan.