The full moon of Kartik, known as Dev Diwali because the gods themselves celebrate Diwali on this night. In Varanasi, the ghats are illuminated with a million lamps. This purnima also marks Tripurari Purnima, when Shiva destroyed the three demon-cities (Tripura) with a single arrow, symbolizing the destruction of the three gunas (tamas, rajas, sattva) that bind the soul. Deep-daan (floating lamps on the Ganges) on this night is considered supremely meritorious.