The Nercha (Russian: Нерча, Buryat: Нэршүү, Nershüü; Mongolian: Нэрчүү, Nerchüü) is a river in Zabaykalsky Krai in Russia, left tributary of the Shilka (Amur's basin). The length of the river is 580 kilometres (360 mi). The area of its basin is 27,500 square kilometres (10,600 sq mi). The Nercha freezes up in October and stays icebound until late April – early May. The town of Nerchinsk is located on the Nercha, 7 kilometres (4 mi) from its confluence with the Shilka.