Lake Khanka is one of the largest lakes in lakes in the world shared between Russia and China along their eastern border. It's in that odd overlap where China is north of Russia and Russia is south of China. Since it is a shared lake between the West and the East its flag reflects this by having an eclipsing sun. The yellow crescent represents the sun, the white crescent represents the moon, while the black middle part represents the overlap. Four stars are visible in honor of night cast upon day which is also an echo of the Chinese national flag. The wavy lines represent the lake.