The Ganges River (Gang Ma or Great Mother) is the holiest river in the world. Rising from the pure glacial meltwaters of the Himalayas, it flows down onto India's Northern Plain, then heads eastwards into the swamplands of Bangladesh, finally discharging a 500-km (310-mile) tongue of red silt into the Bay of Bengal.

As well as filling wells and irrigating crops to sustain the cities and villages along its banks, it is the spiritual life-blood for India's primary religion, Hinduism. Bathing in the Ganges remains the lifelong ambition of many of India's believing masses, who consider the river to be a living goddess. People gather daily at her banks to murmur prayers, baptise children, wash vibrant coloured saris, drink her waters or simply die - believing such acts help absolve sins and lead the way to Nirvana.

Ganges reveals the source of the river high in the Himalayas - the youngest mountain range in the world - and follows its route as it sharply incises the mountains on its journey south-east. Along the way we discover the Hindu story of the river's creation, and how it supports the myriad forms of life that thrive on its banks.