The Mythology of Indra Jatra and the Living Goddess

So Lord Indra took corporeal form and came down from the heavens on his elephant to visit Old Kathmandu. He tied the elephant up at Indra Chowk.

Right here.

He walked out of the city to the flower fields and picked a flower, but was discovered by an angry farmer who tied him up and rolled him into town on a cart. The elephant angrily broke his restraints and crashed around Kathmandu, but was unable to find his master. After eight days Indra revealed himself to be a god in front of the townspeople and they let him go.

Durbar Square.

And that is why in late September the people of Kathmandu celebrate Indra Jatra, the festival of Indra.
Indra brings the rains of the monsoon season, and only after Indra Jatra are children given permission to fly kites in the skies above Kathmandu; this is a sign to Indra that the rains are no longer needed.

Newari Storefront Woodwork.

Over 500 years ago the Malla Kings ruled the three kingdoms of Kathmandu Valley. The ruler of Old Kathmandu was renowned as a wise and great king. However, he had a secret. At night he would leave his house and make his way into an empty dwelling where he would play games of chance with the beautiful and powerful goddess Taleju. She personally would advise him on matters of state on the condition that he and he alone would be allowed to see her and sit in her company.
But the queen became suspicious of the king's late night meanderings and decided to follow him. Hearing a feminine voice behind the door, she angrily threw it open. The beautiful goddess instantly vanished and never returned.

Taleju's Temple.

At least, not directly. Taleju agreed to spiritually inhabit the body of a young girl chosen from a few honored families of the Newari priestly class. Until the day that she first sheds blood, either through injury or menstruation, the chosen young girl is revered as a Living Goddess. She is sheltered and kept hidden away from the public. Except on Indra Jatra.
On Indra Jatra the Kumari rides through the thronged streets of Kathmandu into Durbar Square in a wooden chariot pulled by a dozen or so people with a rope. In front of her, in smaller chariots, ride two young boys of lesser stature that represent the gods Bhairab and Ganesh. The Lakhe, a man dressed in a large mask and said to be possessed by the spirit of a revered demon, dances before the chariot. Other demon dancers perform on various stages. Men possessed of the spirit of Indra's elephant dress up in an elephant costume and dance chaotically through the crowded streets, snatching up dropped items and occasionally knocking over stragglers.

This is the chariot of the Kumari on display the day before.

In the 1760s, when the Nepali-speaking king Prithvi Narayan Shah swept into Kathmandu Valley in his campaign to conquer and unify modern Nepal, he and his people replaced the resident Newaris as the upper caste elite. Yet he bowed down to the young lower caste Kumari and continued the ancient tradition of publicly receiving a blessing from her on Indra Jatra. And each subsequent king publicly received a blessing from the Kumari on Indra Jatra until 2008, when the monarchy was formally abolished.

These are the chariots of Bhairab and Ganesh.