Heixianzi Island, an island system at the junction of Heilongjiang and Wusuli rivers in China, was originally the inherent territory of China and was occupied by the then Soviet Union in 1929. After many hardships and vicissitudes, since 2004, China and Russia have signed an agreement, the western half of which is owned by the People's Republic of China and the eastern half by the Russian Federation. Now it has become a wetland park for visitors to visit!