evidence: According to the agreement to be signed, Russia will return Yinlong Island (Tarabarov Island) and half of Heixiazi Island (Bolshoi Ussuriysky Island). The islands are at the confluence of the Heilongjiang and the Wusulijiang rivers that serve as the natural border between the two countries. [...] The area to be returned is half of the Chinese territory the former Soviet Union occupied during a 1929 border skirmish. In Chinese, the area is collectively referred to as the Heixiazi Islands.