Sthapathis from various parts of India played a role in the renovation process, revealing their skills, adding to the sculptural glory of the temple.  The lord here is called Somanath and Someshwar.  This Siva Lingam that was formed spontaneously is one among the 12 Jothirlingams.  The tank, where Chandra Bhagavan took his holy dips during penance is called Somagundam.

The story: 
Chandra Devan is considered to have built this temple & hence the name Somanathar to the Lord.  Chandran fell in love with Rohini, one of the daughters of Dakshan.  But Dakshan wanted to give all his daughters in marraige to one able & loving person, who would treat all his daughters equally.  Chandran got married to all, but his love for Rohini was too great & the other daughters complained to their father.  Dakshan cursed Chandran to dwindle in power & beauty.   When Chandran begged forgiveness, Dakshan said that only prayers to Lord Siva, could free him of the curse.  Chandran came to Somanath & prayed to Lord Siva, doing penance for about 4,000 years.  Lord Siva appeared & said that he could not fully absolve him of the curse.  Instead, he would wane in 15 days, but would grow again.  This is the story said for the waxing & waning of the moon, producing new moon & full moon.  This temple had been demolished and reconstructed several times.  It was reconstructed in 649 A.D and again in 722 A.D.  From 750A.D - 950 A.D, the temple was well maintained by the Chalukya rulers, after the destruction by Mahmud of Ghazini.  During this period the dome & sthupi were laid in gold.  Once again, the temple was destroyed by Allaudin in 1296 A.D.  The Khengars who ruled from 1325 - 1351, took up the restoration work.  It was later destroyed again by Aurangazeb.  It was reconstructed at a slightly different  spot by Ahalya Bai & was later well maintained by the Baroda rulers.  After Independence, a committe was appointed to reconstruct in the original spot & Sardar Patel played a major role in this reconstruction.