Mudanjiang (Chinese: 牡丹江; pinyin: Mǔdānjiāng; Manchu: Mudan bira ᠮᡠᡩ᠋ᠠᠨ ᠪᡳᡵᠠ) 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 only 248 km (154 mi) from Vladivostok, Russia.