- Amur River
Located in Russia, the Amur River is not considered as a safe river. The river is extremely contaminated and polluted as because of the reason of fish dying in it. The water of this river could cause skin cancer.
- Congo River
Popularly known as “The Heart of Darkness”, The Congo River is located in Africa. It mouths into Atlantic Ocean and is the second largest river in the world. The killer hippos and deadly crocodiles make this river as their home.
- Mekong River
The Mekong flows in five countries of Asia viz. Thailand, Laos, Burma, Vietnam and China. Navigation in this river is impossible because of hostile currents. Lethal predators include Siamese crocodiles.
- Niger River
The Niger River located in Western Africa is 4,180 km long and extremely traitorous. In the year 2010 when its bank was ruptured taking lives 5000 people and 30,000 animals.