Mudanjiang (Chinese: 牡丹江; Manchu: Mudan bira) is a prefecture-level city in southernmost Heilongjiang province, People's Republic of China. It was called Botankou when it was under Japanese occupation. It serves as a regional communications hub with a railway junction and an international airport connecting with several major Chinese cities as well as Seoul Korea. Mudanjiang is also an important border city, located 248 km (154 mi) from Vladivostok, Russia.