On the day of Shivratri, a three-tiered platform is built around a fire. The topmost plank represents 'swargaloka' (heaven), the middle one 'antarikshaloka' (space) and the bottom one 'bhuloka' (earth).
Eleven 'kalash' or urns, are kept on the 'swargaloka' plank symbolizing the 11 manifestations of the 'Rudra' or destructive Shiva.
These are decorated with the leaves of 'bilva' or 'bael' (Aegle marmelos) and mango atop a coconut representing the head of Shiva.
