The answer is India
The extensions of the Indus and Ganges rivers cover more than 2 million km2 and are inhabited by more than a billion people to the present. It is one of the areas in the world with the greatest density of population.
The Indus River became since then the basis for a great and ancient Civilization located in what is Pakistan and northwest India today, on the fertile flood plain of the Indus River. The Ganges river is considered sacred to adscripts to Hinduism, having the name of a goddess.