The Sacred Ganga Talao - Mauritius

In Veerashaivism, Siva divides from His Absolute state into Linga (Supreme Lord) and anga, individual soul, the two eventually reuniting in undifferentiated oneness. There are three aspects of Sivalinga.^{[citation needed]}

The soul (anga) merges with Siva(Linga) by a progressive, six-stage path called shatsthala. This is called Shunyasampadane- earning eternal nothingness.

According to Swami Dharmananda who is a master of Yoga there is a mysterious power in the Linga, its shape has been designed to induce concentration of the mind. Just as the mind is focused easily in crystal-gazing, so also the mind attains one-pointedness, when it looks at the Linga. That is the reason why the ancient Rishis and the seers of India have prescribed Linga for being installed in the temples of Lord Shiva.

The great warrior Arjuna in epic Mahabharata worshipped Linga for acquiring Pashupatasthra, great vedic scholar Ravana in epic Ramayana worshipped Shiva to present his mother Atmalinga, legendary rishi Markandeya and numerous rishis spread across timezones have worshipped the simplest looking Linga. Rishis used to leave all materialism to attain spirituality and a lump of soil in forest was what was required to worship and meditate.

REFERENCE: http://en.wikipedia.org/wiki/Lingam