World believe that the Indus valley civilization is one the very old civilizations of the world. They have the common practice of worshipping Lord Shiva. Researchers found many markings and evidences from the settlements.
The shape of Shiva lingam is again a mystery which has no beginning and no end just as the Lord himself. Shape of the lingam symbolizes the shape of zygote. Every life in the world acquires its first shape as the shape of lingam.