Assisi river, Varanasi. Varanasi is one of the oldest living cities in the world and the ultimate pilgrimage for Hindus, who believe that to die in the city is to attain instant salvation. Varanasi is the tract of holy land lying between the Ganga and the Assi rivers. The Assi river also flows into Ganga. Varanasi is also known as Kashi, the city of light since one of the twelve 'Jyortinglinga's is installed here.