http://thekashmir.wordpress.com/2011/05/16/the-amarnath-pilgrimage-history-facts/#wpl-likebox

Historically, the worship of Shivalingam has been a very popular religious practice in Kashmir. The same stands corroborated by Kalhan Pandit who in his monumental work, Rajtarangini, makes a mention of ‘vateshwar’, an ancient Shiva-lingam worshipped even in his lifetime. A king of Kashmir, Ravana, (1000 B.C)worshipped it as it was believed to predict future occurrences & events through the light emanating from the Sri-cakra engraved on it.1 The king was so devout in his worship of the Shiva-lingam that he consecrated the entire valley of Kashmir to the Math where-in he worshipped the Shiva-lingam.2 The Mahadev Peak, Dyaneshwar lingam &Sureshwar lingam, known as svayambhu lingams, have been objects of worship for the Hindus of Kashmir. In fact, the interiors of Himalayas possess numerous such lingams & Hindus reverently call them Shiva-dhams. Pilgrimages to the Shiva-dhams have been a regular feature without interruptions