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Thirunallar saptha vidanga shrine
Thirunallar has claims to additional impartance as the Second of the seven Saptha Vidanga Sthalas. In other words, this sacred place enshrines a naturally formed Marakatha [emerald] linga known as Navagavidanga which is the second out of the seven images gifted the Indra to a Chola King by name.
Muchukunda, who installed them respectively at Tituvarur, Tirunallaru, Tiruvoimur, Tirukkarayil, Tirukkuvalai [or Tirukkolili], Tirunagaikaronam [Nagapattinam] and Tirumaraikkadu [Vedaranyam] Siva the King of dances, performs the Unmatha dance in this Kshetra.
The sanctum on the left side of Tyagaraja has the Marakathalinga kept in an iron safe. Abhishekas and pujas are offered to it five times a day.
It is computed that there are 17 Sivalingas in this sacred place includind Darbharanyeswara in the main shirne and those that the lords of the 8 cardinal points [Dik Palakas] has established and worshipped along with a sacred tank in each of the cardinal points to which they are respectively accredited.