One of the biggest social events of India, Durga Puja is considered the main festival for Bengalis. It is a ten-day carnival in West Bengal- the eastern state of India, where magnificently created puja pandals are erected at virtually every other street in Kolkata, the capital city of West Bengal. Durga Puja is a celebration of the Mother Goddess, and the victory of the revered warrior Goddess Durga over the evil buffalo demon Mahishasura. Around one week before the festival starts, on the occasion of Mahalaya, the Goddess is invited to come to the earth. The eyes are drawn on the idols of the Goddess on this day, in an auspicious ritual called Chokkhu Daan. After the idols of Goddess Durga have been installed, a ritual is performed to invoke her holy presence into them. This ritual is called Pran Pratisthan. It involves a small banana plant called a Kola Bou, which is bathed in a nearby river, dressed in a sari, and used to transport the Goddess's energy. Prayers are offered to the Goddess every day during the festival. On the third day, Goddess Durga is worshiped in the form of a small girl in a ritual called the Kumari Puja. Worship is concluded with a maha aarti (great fire ceremony). On the last day, worshippers flock to the banks of the river Ganges where the idols are immersed into the muddy waters and the Goddess' spirit is released until the festival begins again the following year.