Soma means moon, Jyoti means light and linga means Shiva.
The Somnath Jyotirlinga is situated at Prabhas, near Veraval, in Gujarat.
The legend goes that Moon had married 27 daughters of Daksh Prajapati. Out of the 27, Rohini was his favourite. This made the other 26 daughters of Daksh Prajapati very jealous. So, they went to their father and complained about Moon’s behaviour. Daksh Prajapati advised Moon to take proper care of all his wives, but it fell on deaf ears. Moon continued to love Rohini. This made Daksh furious, So he cursed Moon saying that he will become weak and will loose his radiance. Moon immediately rushed to Brahma. Lord Brahma told him to chant the Mahamrutyunjay mantra to liberate him from his sin.
Then Moon went to Prabhas and chanted the Mahamrutyunjay mantra 10 crore times. Lord Shiva appeared before the Moon and asked him for a boon. Moon requested Him to liberate him of the curse given by Daksh Prajapati. Lord Shiva told Moon that Daksh Prajapati’s words cannot fail. But, He blessed Moon by saying that for 15 days he will wane and loose the brightness, but the next 15 days, he will gain his radiance by His blessings.
Lord Shiva then established himself as Somnath, at Prabhas. The deities constructed a ‘Kunda’ named Chandrakunda. It is believed that the Moon because liberated from the curse by taking a bath in the Kunda