The Karaga is one of the oldest festivals in Bengaluru. It is held at the Dharmaraya Swamy temple in Thigalarapete during the Chaitra month (usually March or April) and is led by the Thigala community, traditionally gardeners and tank-builders.
On the full-moon night, a priest dressed as Draupadi carries the flower-decked karaga on his head through the old city in an all-night procession. By tradition the procession stops at the dargah of Hazrat Tawakkal Mastan, a gesture of the city's long communal harmony.
Further reading: Bangalore Karaga on Wikipedia.